The shorter the holding time the higher the probability the "trader" is gambling.
Small correction:
your system can be tested to find out the optimal timeframe you should be using. Watch in which timeframe you have the optimal returns.
If you go in a smaller timeframe you will lose return, if you go in a bigger timeframe you will lose return too. So too small or too big timeframes are bad for performance.
In a small timeframe it is very difficult to find the correct direction of the market, and the moves are small, so not much potential to make money. You also need close stops, so big risk to get stopped out. And that combined with commssion and slippage makes it very difficult.
When the timeframe grows you can detect trends, and the moves are bigger, so not more potential to make money. You can use bigger stops, so less risk of getting stopped out.
