Technical analysis could guide somehow to hit the exact time and the right price.
In other hand it is also risky because we think it isa the deepest price but just a moment decline more.
To buy and hold is necessary when the market is down.
Trading could be the second choice.
i agree on your statement it's basically a good strategy to obtain the right time to buy. But in the other hand very risky as well because market is so volatile and very unpredictable. For me must have strategy also and most important patience to prevent being greedy and loss.