http://www.bloomberg.com/news/2013-04-25/cboe-holdings-delays-open-for-exchange-after-system-problems.html?cmpid=yhoo

http://www.tradersmagazine.com/news/ise-gemini-maker-taker-pro-rata-blend-111130-1.html

http://www.thetradenews.com/news/Regions/Americas/Derivatives_tax_proposal_%E2%80%98would_punish_risk_management%E2%80%99.aspx

http://www.tradersmagazine.com/news/bats-goes-after-more-options-market-makers-111131-1.html

http://www.reuters.com/article/2013/04/24/finra-brokercheck-idUSL2N0DB2MU20130424

http://www.foxbusiness.com/news/2013/04/24/cme-group-concerns-prompt-cftc-to-investigate-data-sharing-issue/

http://www.benzinga.com/news/earnings/13/04/3528575/heres-why-your-apple-options-trade-got-crushed-wednesday

http://wallstreetsectorselector.com/2013/04/not-enough-help-for-vix-on-wednesday/

http://www.nasdaq.com/article/options-potential-us-legislation-driving-options-activity-in-solar-companies-japan-construction-move-tipping-coal-producers-cm240272

http://www.chicagotribune.com/business/breaking/chi-cme-group-data-leak-20130424,0,4124230.story

https://theoptionsinsider.com/industry/?p=100013651&qcABC=1

http://www.futuresmag.com/2013/04/23/fake-tweet-erasing-136-billion-shows-markets-still