Today was not a very good day... the downturn looked to be lead by financials - with Moodys cutting BAC, wells fargo, and citi's ratings. Here's something you can use: ETFs, which can follow indexes, groups of stocks, commodities, bonds, currencies.
More specifically, in today's market, the use of INVERSE ETFs would have been the ticket. For example, a Dow inverse etf tracks the dow jones where if the index is down 1%, the ETF will be up roughly 1%. Now I haven't played the game yet so I don't know its available, but today I would've been all over 3x inverse ETFs. These not only inversely track the performance of whatever that ETF follows, but multiplies the returns (or losses) by 3 times. My favorite has always been, and especially in this market is FAZ, a 3x financial bear (inverse) ETF tracking financial stocks. NOTE: I don't know this game, but I always close this position at the end of the day due to "daily rebalancing" which for simplicity let's just say it lessens returns.
We can look at today's biggest gainers on yahoo! finance. What do you see? Inverse ETFs and stocks with prices