An ongoing collection of significant events in market microstructure. I do not include large market moves that occur over the course of the entire trading day. For a list of only stock market crashes, see here. I am also compiling a list of open source microstructure data links.

Timeline

20160226 - NYSE stops accepting stop-limit, stop-loss, and good-til-cancelled orders

20150824 - Low liquidity in first 5 minutes of trading (DJIA -6.6% or 1,100pts)

20131208 - Limit Up-Limit Down (LULD) Phase 2 implementation

20131025 - IEX accepts orders

20130425 - CBOE shuts down for half the day

20130423 - Flash Crash from hacked Twitter account (DJIA -150pts)

20130408 - Limit Up-Limit Down (LULD) Phase 1 implementation

https://www.nasdaqtrader.com/content/MarketRegulation/LULD_FAQ.pdf

20130328 - NASDAQ launches Retail Price Improvement Program

20120801 - NYSE launches Retail Liquidity Program and Knight Capital loses $440mm

20110714 - Compliance date for SEC Rule 15c3-5 regarding risk management for direct market access

20100721 - Direct Edge launches EDGA and EDGX exchanges

20100506 - Flash Crash (DJIA -9% or 1,000pts)

20091005 - Clearly Erroneous Execution (CEE) NYSE Rule 128

200811 - BATS converts ECN to BZX exchange

20070820 - Full implementation of Regulation NMS Rules 610 and 611 (all stocks)

http://www.sifma.org/news/news.aspx?id=2092

20070709 - Implementation of Regulation NMS Rules 610 and 611 (~250 stocks)

http://www.sifma.org/news/news.aspx?id=2092

20070208 - NYSE completes hybrid market

2005 - BATS accepts orders

20010409 - U.S. Equity Decimalization Complete

https://www.sec.gov/news/testimony/052401tslu.htm

20000905 - U.S. Equity Decimalization Begins

https://www.sec.gov/news/testimony/052401tslu.htm

1998 - Direct Edge (Attain) accepts orders

19970120 - Archipelago accepts orders

19970120 - Implementation of SEC Display Rule 11Ac1-4

19871019 - Black Monday (DJIA -22.61% or 508pts)

1986 - First after-market crossing system offered by Instinet

1980 - First direct market access offered by Instinet

19710208 - NASDAQ begins taking orders

196912 - Instinet accepts orders

19291024 - Beginning of the Wall Street Crash of 1929 (Heavy volume slows down ticker)