It has been said that more money has been lost or left on the table by traders trying to pick a top or bottom than most other trading mistakes.
Since following great advice is not my forte...
Let's try a little thought experiment. But first we probably need some foundational information and to be clear-headed on definitions on what is a trend and even what qualifies as a indication of a potential top. Some relevant questions should then be explored leading to a rough outline of a plan of action to investigate further or the creation of some elements in a trading plan.
1. What time frame are we focusing on and why? The long term average return on broad indexes is roughly 9% per year, or about .75% per month. This has been enough of a return to allow some prudent investors to retire comfortably. Intraday trading attracts the most competative minds in the world in search of potentially greater returns, however over 90% of retail traders lose with intraday trading. Why is that? Whenever there is a competition between individuals, game theory should come to mind.
2. Game Theory, Optimized(GTO) strategies seek to engage competition in such a way that is unexpoitable by that competition. This is based on the idea the market is reasonably efficient and thus the players are reasonably, but not perfectly competent, allowing inefficiencies of the competition to accrue to the benefit of the GTO strategy. Another strategy is called exploitive. This strategy can be profitably employed when specific, significant inefficiencies of a class of market participants or structural inefficiencies are identified.
3. Market participants include market makers, hedge funds, retirement funds, and individuals who engage in a variety of strategies and time frames. There are patterns that can indicate which side of the market a particular participant is on. Having a sense of who is doing what can improve one's situational awareness to even providing information that an exploitive opportunity may exist.
4. Tops, which can only ultimately be seen in retrospect, come in several varieties and can leave early indications that a trend change may be imminent. I personally don't start thinking about tops unless price is at least a minimum numbers of ATRs from mean for a given time frame. One this threshold is reached, I look for a potential correction or reversal indication such as range expansion, possibly indicating capitulation of a market participant, or evidence of distribution. Distribution can look like consolidation, with the difference distribution often looks like a roof involving a significant number of bars, whereas consoldation preceding another run up often looks like a flag involving relatively fewer bars. Again, these indicators are in context of current price in relationship to its mean. Distribution often involves a large market participant either unloading inventory or an institution reallocating their portfolio, etc. There are relative volume and tick action considerations as well between the various indications of a top or possible imminent correction.
5. Regardless of the reasons for putting on a trade, we must remember there is event risk and the possibility a market participant is attempting to set up an exploitive situation. In other words, buying opportunities may still exist while searching for a top or correction. If statistics indicate that once a certain threshold is reached, there is a 70% chance the price will reverse to at least the mean using a specific RR, it also indicates that 30% of the time "The top" has not been found. There is a problem with the this line of thinking, though. A reasonable definition of a top seems to include the idea of price reversal. This in turn suggests prices need to trade below the mean, probably beneath the last support as perhaps defined by the mean well. Therefore, again, tops can only be determined in hindsight. Still, there does seem to be a narrow window where exiting a long, at least in part, in an area that often sees the start of corrections may be beneficial.
6. Ultimately, most of what profitable active traders do is related to identifying trade ideas that have been validated statistically which in turn demands back testing. The trick is to properly identify and define each relevant parameter for hopefully solid back testing statistics.