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Been a long time since I posted anything. I'm trying to get back into the swing.

I was struck by this post on Econbrowser about this paper. We often hear "Well, we haven't had a successful break in for the last ten years". Perhaps that doesn't matter. Consider the returns from this hypothetical hedge fund:
1992-1999 was a good time to be in stocks-- a strategy of buying and holding the S&P 500 would have earned you a 16% annual return, with $100 million invested in 1992 growing to $367 million by 1999. As nice as this was, it pales in comparison to CDP's strategy, which would have turned $100 million into $2.7 billion, a 41% annual compounded return, with a positive return in every single year.

Wow. How do you do that?
Want to learn more? CDP stands for "Capital Decimation Partners", a hypothetical fund created by Professor Lo in order to illustrate the potential difficulty in evaluating a fund's risk if all you had to go on was a decade of stellar returns. The strategy whereby CDP would have amassed a hypothetical fortune was amazingly simple-- it simply sold put options on the S&P 500 stock index (SPX).

Buying put options is a way that an investor can buy insurance against the possibility of a big loss. For example, the S&P 500 index is currently valued around 1250. You can buy an option (the 1150 March 2006 put) that will pay you $100 for every point that the S&P is below 1150 on a specified date in March. Such an insurance policy would today cost you about $750. If you've bought enough puts to balance the equity you have invested long, you have nothing to fear if the market goes below 1150, because every dollar you lose on your main holdings you can gain back from your put option.

Now we know! But:
Of course, if you play that game long enough, eventually the market will make a big enough move against you that your capital used to meet margin requirements gets completely wiped out, giving you a long-run guaranteed return on your investment of -100%. But over the 1992-99 period, Lo's hypothetical fund dodged that bullet and ended up turning in a whopping performance.

Lo gives a variety of other examples of funds that could go for a long period with very high returns and yet entail enormous risks. They all have this feature of pursuing investments that have a high probability of a modest return and a very small probability of a huge loss. By leveraging such investments, one can achieve a very impressive record as long as that low probability disastrous event does not occur. It is certainly possible that some strategies along these lines would, unlike Capital Decimation Partners, earn a higher return than the market on average if you stuck with them forever. However, you should view that higher return as coming at the expense of much higher risk.

Now, think about a market where the systemic risk is in fact getting higher. The likelihood of a disasterous event is greater. Then, you have an idea about the information security market. Your past ten years do not matter. What really matters is the information you have in your HR, customer, and financial databases are know worth more money, they are more exposed and if something happens to them you will be required to disclose it.

I think we can expect more Card Systems in the future.

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