Abnormal Returns has a good roundup of links on buy-and-hold.
I often hear the argument that buy-and-hold doesn’t work because the market does in fact occasionally down. Yes, that’s true, but the case for buy-and-hold isn’t for a perpetual rally. Instead, it claims that being in stocks all the time is more efficient than a person’s ability to time the market consistently.
Here’s a stat to consider: On average, the stock market’s best day every 100 trading days is roughly equal to the market’s return average return over 100 days. The other 99% of the time, the market is net flat. So to be a good timer, you have to a really, really good timer. And you get no days off.