I have encountered this problem with ONT and SWH. My strategy was to wait for the first red (1hr, 6hr, or 1d) candle, and buy half position, then wait for days or weeks, buy rest of the half. The first half is the common advice "Never buy at all time highs", and the second part is hedging against more price drops that tend to happen after fast price increases (but this also reduces your potential gain).