Don’t Confuse the Concepts of Winning and Losing Trades with Good and Bad Trades
A good trade can lose money, and a bad trade can make money. 
Even the best trading processes will lose a certain percentage of the time. There is no way of knowing a priori which individual trade will make money. As long as a trade adhered to a process with a positive edge, it is a good trade, regardless of whether it wins or loses because if similar trades are repeated multiple times, they will come out ahead. Conversely, a trade that is taken as a gamble is a bad trade regardless of whether it wins or loses because over time such trades will lose money.
If You Are Out of Sync with the Markets, Trying Harder Won’t Help
When trading is going badly, trying harder is often likely to make matters even worse. If you are in a losing streak, the best action may be to step away from the markets. Clark advises that the best way to handle a losing streak is to liquidate everything and take a vacation. A physical break can serve to interrupt the downward spiral and loss of confidence that can develop during losing periods. Clark further advises that when trading is resumed, the size should be kept small until confidence is regained.
The Road to Success Is Paved with Mistakes
Ray Dalio, the founder of the world’s largest hedge fund, strongly believes that learning from mistakes is essential to improvement and ultimate success. Each mistake, if recognized and acted upon, provides an opportunity for improving a trading approach. Most traders would benefit by writing down each mistake, the implied lesson, and the intended change in the trading process. Such a trading log can be periodically reviewed for reinforcement. Trading mistakes cannot be avoided, but repeating the same mistakes can be, and doing so is often the difference between success and failure.