Resistance: $84,200. A rebound to this level faces pressure, which is a selling point.

Support: $81,100. Falling below this level will accelerate the decline; stop-loss is necessary.

If you want to sell, go short: wait for the price to rebound to around $84,200 and stop rising before taking action.
If you want to exit, set a stop-loss: if the price breaks above $84,650, admit mistake and exit.
Where to look for a decline: first watch $82,000; if broken, then watch $81,100.

Don't guess the bottom; before the trend reverses, bottom-fishing = catching the knife.