Selected articles for topic: exchange bitcoin for ethereum
→ 333 articles
Check also 56 Videos for this topic
Bitcoin Exchange Globitex Granted European Electronic ...
Bitcoin Exchange Globitex Granted European Electronic Money License
Spread the love
Globitex , a new bitcoin exchange co-founded by former Bitcoin Foundation Executive Director Jon Matonis, is announcing that its parent Globitex Holding (Latvia) group company NexPay UAB has been granted an Electronic Money Institution (EMI) license by the Bank of Lithuania, a regulatory authority in the European...
Website:
http://freebitcoin.directory
Buy Bitcoin in Haryana (All Cities), Lowest Rates, Trading ...
Cryptocurrency is a Digital Currency which has been traded in India through the available exchanges. The complete details regarding the exchanges and how to purchase Bitcoin via Exchanges in Haryana. Bitcoin is one of the cryptocurrencies, in which we can trade directly through the INR. The complete process of How to Buy in Bitcoin in Haryana is mentioned below in the article.
Buy Cryptocurrency...
Website:
https://www.buycryptocurrency.info
Related topics : bitcoin buy one exchange sell another / bitcoin buy sell exchange / buy bitcoin exchange rate / buy bitcoin exchange india / buy bitcoin exchange
Bitcoin vs. Ethereum - One Month
Every 10 to 20 seconds
Amount of new token at issuance
12.5 at the moment. Half at every 210,000 blocks
5 per every new block
Utility
Used for purchasing goods and services, as well as storing value (much like how we currently use gold).�
Used for making dApps (decentralized apps) on the Ethereum blockchain.�
Price
Around $17,500 at the moment
Around $800 at the moment
Purpose
A new currency...
Website:
https://learn.onemonth.com
11 ways you can buy bitcoin with a credit card in Canada ...
11 ways you can buy bitcoin with a credit card in Canada
8 January 2018
Buying crypto with a credit card is easy once you know how to go about it.
Buying bitcoin with credit card can be a bit trickier and more expensive than local bank transfers, but there's no shortage of options once you know where to look.
Here are 11 bitcoin exchanges and trading services that operate in Canada and beyond,...
Website:
https://www.finder.com
1 Btc To Usd Daily Chart - btcguard.net
1 Btc To Usd Daily Chart
Crypthatcurrency varyer request put up to you convert option cryptocurrencies to respectively other, something like a. Buy bitcoins! All exchangers. Buy Bitcoin represent the lowest proposition possible! We assess 0:2 20 exchanges that facilitate announce the highest BTC rates represent the allowance machine you nonattendance to application. Who converts Sawith the aim...
Website:
http://www.btcguard.net
Cryptoexchang.com,Trusted Bitcoin and Ethereum instant ...
Monero is cryptocurrency that focuses on privacy and decentralization, popular and globally accepted. Spend or Exchange your Monero to real cash, Paypal transfer, Bank wire, Payza, Perfect money, Neteller, and more
Sell Your Cryto Currency�at Highest�Price
Popular & Reliable Exchange
Bitcoin...
Website:
https://cryptoexchang.com
Buy Bitcoin, Ethereum, & Litecoin In United Kingdom - Coinbase
Buy Bitcoin, Ethereum, & Litecoin In United Kingdom
Coinbase is the easiest way to buy and sell Bitcoin, Ethereum, & Litecoin in
United Kingdom of Great Britain and Northern Ireland
Sign Up To Get Started
Safe & Easy
Coinbase makes it easy to exchange Bitcoin, Ethereum, and Litecoin in United Kingdom. We operate in 32 different countries around the world.
Is Coinbase available in my country?
United...
Website:
https://www.coinbase.com
Related topics : use bitcoin to buy litecoin / use bitcoin to buy ethereum / exchange bitcoin for litecoin coinbase / exchange bitcoin for ethereum coinbase / bitcoin buy one exchange sell another
How do I buy Bitcoin? | Bitpam
In this article we'll be covering how to buy Bitcoin, Ethereum, and Litecoin quick, safely, and easily.
Bitcoin: A movement and money maker
Almost everyone who has heard about bitcoin has probably once thought, "Hmmm, how do I really start buying these Bitcoin things?". It may seem like a daunting task, but after reading this article buying Bitcoin will be one of the easiest things you've ever...
Website:
https://bitpam.com
Bitcoin Australia
admin Comments 0 Comment
How to trade Bitcoin and Altcoins?
If you are in Australia and you can buy or trade Bitcoin and Altcoins in Coinspot.com using Australian Dollars.� Before you can start buying coins, you need to setup an account first.� If you want to see a review of Coinspot, click here.
The coins currently available at Coinspot are, Bitcoin, Ethereum, Bitcoin Cash, IOTA, Ripple,...
Website:
https://bitcoinaustralia.net
Top 5 Cryptocurrency Exchange Site - Best place to buy and ...
If you are looking to buy your first Bitcoin, choosing an online exchange is the very first step you need to take.
I was being asked all the time what are the best places to buy Bitcoin and Cryptocurrency so I�decided to create this guide for you.
To help you get started investing in Bitcoin, I curated for you the top 5 cryptocurrency exchanges that I use personally. You can buy your first...
Website:
https://www.alexfortin.com
Indianapolis Bitcoin Atm - btcguard.net
Indianapolis Bitcoin Atm
Alert stipulation debit falls under. Choose your Bitcoin parade. XBT with the aim of facilitate USD acceptance atlas XEs forgive living so as thatlerance revision diagram in shappeningport of Bitcoin to US Dollar allows you to team disagreement control archive in lieu of up to bitcoin debit card shift 10 yearsThe CoinDesk. Bitcoin additionally supplementary crypto...
Website:
http://www.btcguard.net
Ice3x bitcoin exchange South Africa
Create your free iceCUBED account on the bitcoin exchange & start trading bitcoin today!
What Is Bitcoin (XBT | BTC | ) ?
Bitcoin is Internet Currency. As a currency, bitcoin does not suffer from the limitations of physical "FIAT" currency, and has greater flexibility and security, with the transaction cost far lower than similar solutions. Bitcoin is totally secure and the network has never...
Website:
https://ice3x.co.za
BitCoin Buy Sell Signals (CryptoCurrency) - Forex Trading ...
Live Daily BitCoin Buy Sell Signals (CryptoCurrency) by FxPremiere Group - the Leading Signal Provider Worldwide!
BitCoin Buy Sell Signals (CryptoCurrency)
BitCoin Buy Sell Signals (CryptoCurrency) from FxPremiere Group. Today the world of Signals for BitCoin Buy Sell Signals (CryptoCurrency) is immense with Signals from hundreds if not thousands of providers.
BitCoin Signaling Chart
FxPremiere...
Website:
https://www.fxpremiere.com
Coinhako Review: Bitcoin Exchange and Wallet for Malaysia ...
Coinhako Review: Bitcoin Exchange and Wallet for Malaysia and Singapore
What is Coinhako?
Coinhako is a Bitcoin wallet and exchange based in Singapore and it is one of the most user-friendly platforms for both residents of Malaysia and Singapore to buy and sell Bitcoin.
Coinhako was founded in 2014, and it started as the Bitcoin platform allowing people in Singapore to convert fiat currency into...
Website:
https://managingyourfinance.com
How To Buy Bitcoin or Ethereum in Kenya and Make Money Easy
By David Koech � / � Wednesday, 14 Jun 2017 07:00AM � / � 12 Comments � / � Tags: Bitcoin , Ethereum
It is the biggest thing in the world right now, but Kenyans are sadly missing out.
Unlike the many get rich schemes people keep falling for, Cryptocurrency is the future of finance, and as more people get into it, their value is growing exponentially.
Everyone knows Bitcoin. You...
Website:
http://nairobiwire.com
Parabolic Coin
When writing an article about the recent move in bitcoin, one should probably not begin by preparing the chart images. Chances are one will have to do it all over again. It is a bit like ordering a cup of coffee in Weimar Germany in early November 1923. One had to pay for it right away, as a cup costing one wheelbarrow of Reichsmark may well end up costing two wheelbarrows of Reichsmark half an...
Website:
http://www.acting-man.com
Bitcoin Wallet Kaise Banaye
Bitcoin Wallet Kaise Banaye
Thanks a lot for coming to The Unity Ingot in searching for "Bitcoin Wallet Kaise Banaye" online.
The Bitcoin took the world of financing by shock when its value increased by 15,000% within 4 years, as the cost each Bitcoin surged from $0.08 to $1,200! The underlying need for an independent electronic money, not managed by a central federal government which undergoes...
Website:
https://bitcoinpools.net
eBitcoin | eBitcoin Resources and Information.
PR & Media
patrick@ebtctoken.org ">Patrick
There are about 30 more volunteers in our Team, who help eBitcoin with different skills. We thank them, for being part of and joining our mission.
Team Page
Support eBitcoin
This has been quite some journey already and we have just started. Crypto-enthusiasts, please show your unweavering support and enthusiasm for eBitcoin by going to CEX.io and...
Website:
https://ebitcoin.org
Related topics : exchange bitcoin for ethereum / use bitcoin to buy ethereum / using bitcoin for currency exchange / digital currency payment system / bitcoin cost per transaction
Bitcoin Calculator Gpu - bitcoin-charts.net
Throughout your look for the most effective information concerning "Bitcoin Calculator Gpu". Tell your good friends you found it below!
The Bitcoin took the globe of financing by surprise when its worth enhanced by 15,000% within 4 years, as the price per Bitcoin surged from $0.08 to $1,200! The underlying need for an independent digital money, not managed by a main federal government which...
Website:
https://bitcoin-charts.net
Coinbase Review: Is Coinbase Safe to Buy Bitcoin in 2018?
Home » Coinbase Review: Is Coinbase Safe to Buy Bitcoin in 2018?
Coinbase Review: Is Coinbase Safe to Buy Bitcoin in 2018?
January 10, 2018
Share Tweet
With the beginning of 2018, buying crypto has a hot pie which everyone wants to taste.
With the recent price spike of Bitcoin and Ethereum, almost everyone wants to get there share of BTC. But the question arises, how to buy Bitcoin/Ethereum?
So,...
Website:
https://coinscage.com
Buy Bitcoins | Bitcoin Exchange - BTC Markets
Support
How To Buy Bitcoin
So you want to buy Bitcoin? This guide shows you step-by-step the easiest and quickest way to buy Bitcoin.
1. Create Account
Create a BTC Markets account. This will give you a secure place to store, send and receive your Bitcoin.
2. Verify Your ID
Complete your profile and then follow the prompts to verify your identity. Once verifed, you are ready to fund your account....
Website:
https://www.btcmarkets.net
How to buy bitcoin & other cryptocurrencies - Blockchain ...
�
What is a Cryptocurrency?
Cryptocurrency is a type of digital asset used as a medium of exchange. The most famous one is Bitcoin. Other common terms for cryptocurrencies are digital tokens or digital assets. They are all stored in distributed ledgers called blockchains. Each blockchain has its own digital token. In the case of Bitcoin, it is the Bitcoin token. Other examples are Ethereum,...
Website:
https://blockchainhub.net
Where to buy Bitcoins?
A Guide to Bitcoin Exchange Services
Bitcoin Exchange
Bitcoin is a form of digital currency (also known as cryptocurrency) similar to Ethereum and Zcash. Bitcoin was created in the year 2009 by an anonymous person who goes by a pseudonym "Satoshi Nakamoto". There are other digital currencies in existence but why is that only bitcoin has become such a rage?
That is not without reason. At the time...
Website:
https://www.wheretobuybitcoinstoday.com
Your own Instant Exchange Gateway. Forever.
Minimum exchange volume is 0.1 ETH or equal 0.1 ETH in BTC!
Please don't send less - transactions will be lost!
Need Ether for Bitcoin or vice versa? Enter your Ethereum wallet address once, and get YOUR OWN permanent Bitcoin exchange address. Any Bitcoins sent to this address will be automatically converted to Ethereum and sent to your Ethereum wallet. No need to fill the forms on website, just send...
Website:
https://gateway.stex.exchange
Related topics : get a bitcoin wallet address / bitcoin wallet address / get a bitcoin address online / all used bitcoin addresses / all bitcoin addresses
Guide: How to Buy and Trade IOTA Cryptocurrency from India
Home Online Services Financial Guide: How to Buy and Trade IOTA Cryptocurrency from India
Guide: How to Buy and Trade IOTA Cryptocurrency from India
December 7, 2017
Bitcoin doesn't need an explanation anymore. It's the first and the most valued cryptocurrency in the world right now. If you heard about Bitcoins, you might also have come across Ethereum or Litecoin or Bitcoin Cash as...
Website:
https://www.techmesto.com
Blockchain Meetup Berlin (Berlin, Deutschland) | Meetup
Blockchain Meetup Berlin with your bitcoin donation:
1HWgB3DKDe8TJVesSD3EkZk7Raj5Q82hkB
Other Blockchain/Bitcoin/Cryptocurrency Events:
Bitcoin Exchange Berlin ( http://www.meetup.com/Bitcoin-Exchange-Berlin-BXB/ ): Every Monday. Informal. Buy and sell bitcoins and get help in setting up wallets and...
Website:
https://www.meetup.com
Related topics : bitcoin buy sell exchange / get a bitcoin wallet / buy bitcoin exchange website / buy bitcoin exchange / bitcoin blockchain wallet
Keep Your Bitcoins Safe With a Hardware Wallet – Block ...
Your wallet app shows you have a certain amount of Bitcoin that you can spend based on the transaction inputs received by your public address. To spend it, your wallet application takes one or more transaction inputs, encodes it with your private key and your receiver's wallet address, then sends that encrypted message out to the closest Bitcoin node. The transaction gets included in the next 10...
Website:
https://blockoperations.com
Bitcoin Mining Digitalocean
The most effective details to feed your mind on "Bitcoin Mining Digitalocean" is discovered below.
The Bitcoin took the world of financing by shock when its value boosted by 15,000% within four years, as the cost each Bitcoin rose from $0.08 to $1,200! The underlying need for an independent digital currency, not managed by a central federal government which is subjected to their measurable easing...
Website:
https://bitcoinpools.net
How to Trade Cryptocurrency - For Beginners ...
We explain how to trade cryptocurrency �for beginners. To start trading cryptocurrency you need to choose a cryptocurrency wallet and an exchange to trade on.
From there it is as simple as filling out a form and waiting for the transaction to process (once your information is verified with the exchange you pick).
In other words, if you want to trade cryptocurrency you need:
A cryptocurrency...
Website:
http://cryptocurrencyfacts.com
How to Buy and Sell Bitcoin in India | techcresendo
Cryptocurrencies in India:�How to Buy and Sell Bitcoin in India
Cryptocurrencies in India:�How to Buy and Sell Bitcoin in India
Investment opportunities in digital cryptocurrencies have been constantly rising over the past few years.�Bitcoin was recently in the news because of the�ransomware WannaCry. The Wanna Cry cyber attacks were one of the biggest attacks of this sort, affecting...
Website:
http://techcresendo.com
Bitcoin and Ethereum crash: Can you get rich from a price ...
Bitcoin and Ethereum crash: Can you get rich from a price drop? 3 alternative ways to invest
Published
The cool crypto kids have moved beyond merely buying and selling ether. Wit Olszewski/Shutterstock
The cool crypto kids have moved beyond merely buying and selling ether. Wit Olszewski/Shutterstock
Thinking about investing in a virtual currency like bitcoin or Ethereum-traded ether ? These...
Website:
https://mic.com
Bitcoin Fork Countdown Monitor | forkCountdown.org
What is Bitcoin?
Bitcoin is the first digital peer-2-peer decentralized "cryptocurrency".
It was created in 2009 by "Satoshi Nakamoto" (an anonymous person/group) in 2008 and officially released a year later. At first Bitcoins could only be mined and not bought. Mining is the process where computers run software and exchange computing power for Bitcoins.
What is a fork?
A fork is when a cryptocurrency splits into two, yeilding free additional currency of another type.
It occurs when a cryptocurrency's existing code is changed, resulting in both an old and new version. While the old version of the code continues to exist and function as it did...
Date: 2018-01-19 23:01:38
Website:
http://forkcountdown.org
Crypto Exchanges – Buy & Sell the Currency of Your Choice
Crypto exchanges are similar to the ways fiat currencies are traded. Cryptocurrencies are also bought at a certain price. This price fluctuates against the value of other currencies. There are several factors that affect these price movements. That's also why the value of cryptocurrencies varies from time to time. Typically, the price movements are more often and more significant.
Cex.io -...
Website:
https://www.coinchoose.com
Bitcoins: Latest News, Photos, Videos on Bitcoins - NDTV.com
TRON (TRX) Falls 5%. Five Things Cryptocurrency Investors Should Know
Business | NDTV Profit Team | Thursday January 11, 2018
Tron (TRX) trades at $0.111838 on Thursday, as the data given by CoinMarketCap. The price is the average price of 36 stock exchanges that deal in Tron worldwide.
Bitcoins Will Come To A Bad End, Says Warren Buffett. Ten Things To Know
Business | NDTV Profit Team | Thursday...
Website:
https://www.ndtv.com
Bitcoin to PayPal | BTC Exchanging made easy!
0 Min. reading
How to transfer: Bitcoin to Paypal
After earning some Bitcoin via Cloud Mining and HYIPs we got to the point, that we want to transfer some of the profits and earnings out of our Wallet. But then we asked ourselves the question: How to exchange Bitcoin to PayPal?
It was more or less easy to buy Bitcoin, but to sell Bitcoin without paying high fees in a secure way was not easy....
Website:
https://www.coinstaker.com
Download Exodus
Even more bitcoin fee optimizations - with rising Bitcoin prices every little satoshi helps.
Exchange
Exodus now has an exchange history view to browse all exchanges in one central location.
The new history drawer calculates your overall percentage change for each of your Exodus exchanges.
The new contact Exodus button in the history drawer to allow users to make contact with Exodus and pre-fill...
Website:
exodus.io
Download Exodus
Even more bitcoin fee optimizations - with rising Bitcoin prices every little satoshi helps.
Exchange
Exodus now has an exchange history view to browse all exchanges in one central location.
The new history drawer calculates your overall percentage change for each of your Exodus exchanges.
The new contact Exodus button in the history drawer to allow users to make contact with Exodus and pre-fill...
Website:
exodus.io
LocalBitcoins & Shapeshift.io – the fastest way to buy ...
The fastest way to buy Ethereum (ETH) is, oddly enough, to first buy Bitcoins and then to convert it to Ethereum. Don't lose out waiting several days for an international bank transfer, use LocalBitcoins and Shapeshift to make the transaction in less than a day.
TL;DR, how do I do it?
The shorthand version, follow these four steps.
If you're not signed up, register for an account on LBC .
Search...
Date: 2018-01-02 12:51:11
Website:
localbitcoins.blogspot.com
Related topics : use bitcoin to buy ethereum / buy bitcoin with online bank transfer / localbitcoins buy with bank transfer / buy bitcoin bank transfer / fastest way to buy bitcoins online
Bitcoin: Learn How To Trade Crypto at Commodity.com
Remember that your capital is at risk
Can You Trade Bitcoin Futures?
In December of 2017 CME group , one of the largest financial exchange organizations in the world, allowed traders to exchange the first Bitcoin futures contracts. This was considered a significant milestone for the cryptocurrency and resulted in a spike in Bitcoin's value.
Bitcoin futures trading works on the same principle as...
Date: 2018-01-11 14:48:38
Website:
https://commodity.com
Bitstamp to Add Bitcoin Cash Trading in December ...
Bitstamp to Add Bitcoin Cash Trading in December
Matthew Neuteboom · November 25, 2017 · 8:45 pm ·
Views: 4,133
News teaser
Cryptocurrency exchange Bitstamp will support three Bitcoin Cash trading pairs - BCH/USD, BCH/EUR, and BCH/BTC - starting the first week of December due to customer demand.
Bitstamp, the twelfth largest crypto exchange by volume and the seventh highest ranked exchange on...
Website:
http://bitcoinist.com
5 Best Bitcoin and Ethereum Apps for Android
Bitcoin Billionaire
Bitcoin Wallets
A Bitcoin wallet is a software- or hardware-based tool that allows you to start making payments with merchants and users using Bitcoin, the infamous cryptographic currency that once powered Silk Road , an online black market owned by Ross Ulbricht and the first modern darknet market.
Back in 2011, when Silk Road launched, there weren't that many Bitcoin wallets...
Website:
https://thedroidguy.com
Top Bitcoin & Ethereum (Cryptocurrencies) IRA Companies in ...
US Only
Read Full Review
IMPORTANT: we would like to remind you that cryptocurrencies are a highly risky and speculative investment. If you are not an accredited investor, do your due diligence and make sure you understand how cryptocurrencies like Bitcoin work. Do NOT invest any sum of money that you couldn't afford losing. Many experts, like Mark Cuban, recommend that no more than 10% of one's...
Date: 2017-12-30 04:49:09
Website:
https://goldiraguide.org
Home – Cryptocurrency Brokers
* Risk Warning: Trading CFDs on margin carries a high level of risk, and may not be suitable for all investors. Losses can exceed investment.
** Funding methods can vary with each broker and country. Please visit broker's website for accurate local information.
Live Charts
"
WHAT ARE CRYPTOCURRENCIES?
Cryptocurrencies first appeared with the creation of Bitcoin in 2009--today, they're the hottest...
Website:
https://www.cryptocurrency-brokers.com
mining pool url | Bitcoins In Ireland
Or read our full list of bitcoin gambling articles.
Looking to buy or sell bitcoin or ethereum?
CEX allows you to quickly buy bitcoin or ethereum with your credit or debit card, although at a small premium to market rates. Click here to buy Bitcoin with your credit card .
If you don't mind going through the rigmarole and verification to set up an exchange account and want to get the best market...
Website:
https://bitcoinsinireland.com
List of mining pools who have mined bitcoins | Bitcoins In ...
Or read our full list of bitcoin gambling articles.
Looking to buy or sell bitcoin or ethereum?
CEX allows you to quickly buy bitcoin or ethereum with your credit or debit card, although at a small premium to market rates. Click here to buy Bitcoin with your credit card .
If you don't mind going through the rigmarole and verification to set up an exchange account and want to get the best market...
Website:
https://bitcoinsinireland.com
Genesis Ethereum Calculator - Genesis Mining Promo Code
Please Share
What is Ethereum
You may not have discovered, but ethereum is under attack. Recently Ethereum became popular by investors. For the very first time, Ethereum provides an alternate.
Ethereum is a new type of law. Like every blockchain, Ethereum also has a peer-to-peer network protocol. Ethereum is among the latest things on earth of cryptocurrencies. Ethereum gets rid of the demand for...
Etherum Price | ETH USD | Chart | Etherum US-Dollar ...
Just when you thought you had your head around bitcoin, along comes Ethereum.
The word has been in a lot of headlines as the cryptocurrency world's new favorite thing soared in value. The ethereum price of something called an ether token grew in value up over 3,000% from 2016 - 2017.
Bitcoin, which is far more widely known as an alternative 'currency', is up about 141% in that same time.
But what...
Website:
http://markets.businessinsider.com
Related topics : ethereum bitcoin price chart / use bitcoin to buy ethereum / exchange bitcoin for ethereum / bitcoin value one year ago / bitcoin one year ago
BENENIEX
Beneniex is a full-featured spot trading platform for the major cryptocurrencies
BENENIEX
Trade securely on the world's most active digital asset exchange.
About US
When one considers the overall efficiency of modern information and communication systems, the level of disconnectedness and inefficiency of the world's financial infrastructure is truly astonishing: transactions are...
Website:
http://beneniex.com
Related topics : bitcoin debit card us / virtual bitcoin debit card / exchange bitcoin for ethereum / exchange bitcoin for litecoin / bitcoin atm card free
Bitcoin mining pool for Android Free Download - 9Apps
Bitcoin mining pool latest version on 9Apps for free every week! The world's most powerful app is here waiting for you. This hot app was released on 2017-10-02. You can quickly get it from 9Apps!
The highest paying Bitcoin mining pool and cloud mining provider on the market. Start mining Bitcoin today!
Start mining cryptocurrencies on the go! Most promising altcoins, such as Bitcoin and ETH, wallet stats and more. Make a...
Website:
https://www.9apps.com
Exchange cryptocurrency - Bitcoin Ethereum Monero Ripple ...
You can buy Bitcoin, Ethereum, Monero, Zcash, Ripple and other crypto for USD instantly!
Visa and MasterCard accepted here?
Do you like Changelly? Rate us on TrustPilot!
150+ positive reviews on Trustpilot?
Fair
Other cryptocurrency trading services charge you with withdrawal fees and commissions. We have a reasonable fee of 0.5%.
Fast
Enter the amount and the address. Transfer your coins and let the magic happen.
Trusty
Changelly is presented to you by...
Website:
https://changelly.com
Related topics : use bitcoin to buy ethereum / buy bitcoin exchange rate / bitcoin coin exchange rate / use bitcoin to buy ripple / current bitcoin exchange rate