The DIA and SPY are two ETFs which track the Dow Jones Industrial Average and the S&P500, respectively. You can buy and sell those. You can also buy and sell options. This is much cheaper than buying and selling the DIA and SPY, but also much more risky. I currently have some DIA puts and was up 17% on Monday and then down 13% yesterday. My total options investment is only around $4,000 though.
Whatever you do, I recommend starting very small until you get used to how things trade. For example, the spreads on option contracts are typically big and they can go several days without trading. If the strike prices on the options you buy are closer to the current trading price of the underlying security, the market will generally be fairly liquid (although not always!).
