One thing that has been clear to me over the last couple of years is that ETF innovation would allow do-it-yourself investors to have cheap and easy access to potentially sophisticated strategies.The latest batch of ultra short (i.e., double short) sector funds are a big step in this direction for market-neutral strategies and paired trades. ProShares has listed 11 funds that go short various Dow Jones versions of different sectors. In this article, I will profile a possible strategy that I think could be applied to all of them, so roll up your sleeves. The example here will be with the financial sector, the Ultra Short Financials ( SKF). This fund captures double the inverse of the Dow Jones Financial Sector Index. The proxy for this index exists as a single long ETF: the iShares Dow Jones Financial Sector Index Fund ( IYF). To be clear, $10,000 in IYF paired with $5000 in SKF, save for whatever the tracking error might be, would offset each other on a daily basis. There are two types of paired trades that could offer very good results (think bases on balls and hit by pitch) with very little market risk.