Why did Ferrari $Ferrari(RACE.US) accelerate its decline after I liquidated my position in two batches near 490? Today I also closed my position in Walmart $Walmart(WMT.US).

This is what we call profit-taking. Profit-taking isn't as simple as stop-loss. For stop-loss, you just need to set a price you're unwilling to lose beyond and leave it there. But profit-taking requires a target price first. No matter at what price you bought in, you need a predefined target. For Ferrari, my target was around 480. When the price reached my target and showed signs of weakness, I wouldn't hesitate to sell, even executing a market order during trading hours. I can't sell at the highest point, just like I can't buy at the lowest.

Today I closed my Walmart position without knowing whether it would drop. I just followed my trading plan where my target was only 80. My average selling price was 79.7. I didn't sell at the peak nor at 80, because after reaching the target, I still needed to see clear signs of weakness. Of course, I don't know whether Walmart will rise or fall tomorrow or even hit new highs.

In conclusion, none of us are prophets. Don't assume new highs just because of previous peaks, or aim for 100 when you see 90. Extreme price volatility easily makes people lose rationality.