If you've spread your money across many alts then hold them and wait. Each one of them will probably pump at its own time and in the end you'll have made your profits. What's the point in selling now? Everything is red on the board. If you already have coins that you thought were sound investment a few days ago, why would you change them now for other coins that are also getting dumped and on top of that also lose money in the process.
Firstly I plan to retain most my positions for the long run, but if I were to exit, I would move from smaller more speculative cryptocurrency to larger, more stable ones like Ethereum/BTC. Ethereum will have much less downside than some of the small cap ones with weak fundamentals. Also, I am not trying to exit before the top, I would let the bubble finish, and then take profit in the next weeks after that it is clear the bubble is finished (which we will know because the steady growth will have stopped).