Hold tight and wait for it going up again.
Grab more token if this thing happen because this is the best time to accumulate more bitcoin specially, don't panic because it will surely bounce back. The only problem with people is that they are fear to loose money that will really happen when they sold their token at a loss. So just stick to your plan and be more patience you will surely succeed in the future, Invest more on btc.
Correct when the value of coins are falling specially on bitcoin you should hold it and the value will recover after the big dump happen. Panic selling will result to loosing the opportunity to earn more profit, if you are in crypto world you should know that value are volatility when you invest you should set the target amount to sell your coin to avoid panic selling.