Actually if there's any one lesson to be learned from the last dozen years of the stock market's swings, it is that "buy and hold" is dead as a useful investment strategy.

As to gambling vs. trading, there's a whole industry of people who train traders in eliminating the gambling psychology that can destroy equity so quickly. A short time frame only exacerbates the psychological weakness.

Oddly enough successful day traders, that is, those who hold their positions for mere minutes and close out all positions by the close of the trading day, are about as far from gamblers (in a psychological sense) as you can get.