In a log chart of BTC, by drawing diagonals from bear market lows we can find where market will top at the end of a cycle. Yellow highlighted bottom goes on to form yellow highlighted top (ray1), green highlighted bottom goes on to form the green highlighted top (ray2)
It is not possible to know where current cycle will top at before the bear market ends with this method but it'll be possible once we are well into the next bull market. Draw a diagonal from bear market lows and wait for price to hit your diagonal from below. This is not enough to open a net short position as 2021 top shows (since it double topped) but enough to exit your long position