http://money.cnn.com/2013/04/24/investing/twitter-flash-crash/index.html?source=yahoo_quote

http://www.chicagotribune.com/business/breaking/sns-cme-group-puts-kansas-city-grain-exchange-building-up-for-sale-20130423,0,4094927.story

http://www.fool.com/investing/general/2013/04/23/do-investors-need-twitter.aspx

http://www.businessweek.com/news/2013-04-23/crude-oil-options-volatility-declines-as-new-york-futures-slip

http://www.livetradingnews.com/sec-probe-gives-cboes-in-house-supervision-unit-a-headache-111751.htm#.UXfZ6Mrm-ds

http://www.bloomberg.com/news/2013-04-24/ice-nyse-deal-will-be-reviewed-by-eu-antitrust-authority-1-.html

http://www.bloomberg.com/news/2013-04-24/cboe-said-to-consider-separation-of-regulatory-unit-from-company.html

http://online.barrons.com/article/SB50001424052748703889404578440863954358222.html?mod=BOL_columnist_latest_col_art

http://blogs.barrons.com/focusonfunds/2013/04/23/what-a-global-market-does-when-aps-twitter-account-is-hacked/?mod=BOL_hpp_blog_fof

http://www.bloomberg.com/news/2013-04-23/u-s-stock-options-with-biggest-changes-in-implied-volatility.html?cmpid=yhoo

http://www.bloomberg.com/news/2013-04-23/liffe-sues-dutch-options-market-tom-over-aex-products.html?cmpid=yhoo

http://blogs.wsj.com/moneybeat/2013/04/23/stocks-plunge-quickly-recover-on-fake-tweet/