Old coins and small pools that surge suddenly are not recommended:
A sudden spike in a small pool is generally due to a celebrity suddenly promoting something, causing this coin to ride the wave. If the market happens to be good during this time, there are definitely a lot of people waiting to jump in at the bottom. The first wave of people who rush in after the spike are either real-time monitoring bots or the smartest and most keen traders in the market. If you still want to jump into such pools at this time, you are just adding to the exit liquidity for the other side.
The logic behind not jumping into these types of pools is not hard to understand. These bots and traders have no emotional attachment to this coin; don't think they will HODL for more than 10 minutes. Similarly, if a pool is slowly rising, it is mostly due to a decent community behind it, as the emotionless traders have mostly already exited along the way.