January
01-08 Bitcoin Pooled Mining reached a total of 10,000 Mhash/s
01-27 Largest numeric value ever traded for bitcoins thus far occurred on this date. Three currency bills from Zimbabwe, known as Zimdollars, were traded on #bitcoin-otc at the rate of 4 BTC for each of the one-hundred trillion dollar ($100,000,000,000,000) Zimbabwe notes1
01-28 Block 1050002 was generated. This means that 5.25 million bitcoins have been generated, which is just over one-quarter of the eventual total of nearly 21 million.
February
02-09 Bitcoin reached parity with the US dollar, touching $1 per BTC at MtGox.
02-10 Bitcoin.org website struggles to handle traffic3 resulting from mentions on Slashdot4, Hacker News and Twitter following the news that parity had been reached.
02-14 A vehicle was, for the first time, offered in exchange for a certain number of bitcoins5.
March
03-01 MagicalTux buys mtgox.com from its founder Jed McCaleb
03-06 Total Bitcoin network computation speed for a short time reached a new high of almost 900Ghash/sec, dropping to 500Ghash/sec soon after. Some speculate that this was due to some supercomputer or bot-net that joined the network (mystery miner).
03-18 BTC/USD exchange rate reaches a 6-week low point at almost $0.70/BTC, after what appeared to be a short burst of, possibly automated, BTC sales at progressively lower prices. BTC price had been declining since the February 9 high.
03-22 WeUseCoins releases the viral What Is Bitcoin? video which has had more than 10 million views.
03-25 Difficulty decreased nearly 10%. A decrease has only occurred once before, and this decrease of nearly 10% was the largest.
03-27 The first market for exchanging bitcoins to and from the British Pound Sterling BTC/GBP, Britcoin, opens.
03-31 The first market for exchanging bitcoins to and from Brazilian Reals, Bitcoin Brazil, opens.
April
04-05 The first market for exchanging bitcoins to and from the Polish złoty, BitMarket.eu, opens.
04-12 First bitcoin put option contract sold via the #bitcoin-otc market.
04-16 TIME does an article on Bitcoin.
04-23 BTC/USD exchange rate reaches and passes parity with the Euro (EUR) on MtGox exchange.
04-23 BTC/USD exchange rate reaches and passes parity with the British Sterling Pound (GBP) on MtGox exchange.
04-23 Value of the Bitcoin money stock at current exchange rate passes $10 million USD threshold.
04-27 VirWoX opens first market to trade bitcoins against a virtual currency on BTC/SL (Second Life Lindens) exchange.
04-30 The generation difficulty passed 100,000.
06-02 The exchange rate at MtGox touched 10 USD per BTC.
06-08 The MtGox exchange rate peaked at 31.91 USD, at a “market capitalization” of about $206 M6.
06-12 The MtGox exchange rate briefly dropped to near 10 USD four days after the peak, in its largest percentage price retreat to date.
06-13 Forum user allinvain claimed to have had 25,000 BTC stolen from his Bitcoin wallet.
06-19 The MtGox database was compromised and the user table was leaked, containing details of 60,000 usernames, email addresses and password hashes, some of which were overly simple to brute force passwords.
06-19 Someone was able to access an admin account at MtGox and issue sell orders for hundreds of thousands of fake bitcoins, forcing the MtGox price down from $17.51 per bitcoin to $0.01. MtGox announced that these trades would be reversed. Trading was halted at MtGox for 7 days (and also briefly at TradeHill and Britcoin while their security was reviewed).
06-19 Some of the users on the leaked MtGox database had used the same username at MyBitcoin and had their passwords hacked. About 600 of them had their balance stolen from their MyBitcoin accounts. One user lost over 2000 BTC.
06-20 The EFF announced that it was no longer accepting Bitcoin donations due to legal uncertainties.
06-24 The generation difficulty passed 1,000,000 with Block 1330567.
July
07-19 “Let it go on record that at 4:05pm CET [19 July 2011], my manager Tadek was the first person in the world to receive [testnet] Bitcoins via NFC ;)” - Mike Hearn
07-22 BitCoins Mobile, the first Bitcoin application for iPad was released by Intervex Digital.
07-26 Room77 becomes the first brick-and-mortar business (bar) to accept Bitcoin as a means of payment.
*07-30 Tribute to Len Sassaman included in the blockchain8.
August
08-20 First Bitcoin Conference and World Expo held, in NYC.9
07-23 P2Pool, the first P2P decentralized pool, mines its first Bitcoin mainnet block (Block 14231210).
07-30 Difficulty adjustment at block 14313611 marks the first back-to-back drop.
November
11-15 First CVE (CVE-2011-4447) assigned to a Bitcoin client exploit.
11-25 First European Bitcoin Conference in Prague, Czech Rep.12
December
- 12-12 Largest amount of fees, to-date, in a single transaction13, and most fees in a single block. A transaction paid 171 BTC in fees in block 15723514.
Serial numbers for Zimdollars sold: AA1669317, AA1669318 and AA1669319 ↩
bitcoin.stackexchange: “Market capitalisation” over time ↩
bitcointalk.org: A Tribute to Len “rabbi” Sassama ↩
New York Conference 2011 ↩
Prague Conference 2011 ↩