You'd be looking at around $12k. Bitcoin's previous highs were all coming out top at around $12k and just before it hits that $12k mark, the prices have plummeted. This happened twice already, which means that $12k is the major resistance to look out for here.

If you think that BTC will fail to breach $12k completely the third time, then sell at around $11.5k.

If you're more bullish, aka if you think it's going to go higher, then I would recommend selling at $13-14k. There is a chance that BTC won't even hit $10k once more, so you could sell at the current level if you wanted to. You do have a lot more flexibility in your decisions if you bought at the bottom of the dip.