I came across this issue last minor dip. I use bitShares to do some of my trading for the coins that I can trade on it. It has a really nice USD derivative similar to USD Tether (USDT) called bitUSD. I realized next time my portfolio went up too fast too quick, and I put converted some of my crypto holdings into bitUSD which stays at 1 USD in value when converted to bitShares (BTS). Then when the markets dipped again, I could instantly convert my bitUSD to BTC or BTS and convert to other altcoins from there. Also, the bitShares exchange is really nice because it eliminates a lot of the trust issues users have with exchanges as it's a decentralized exchange and the fees per trade is a really cheap flat fee:

Check it out if you're looking for a stable store of value when the crypto markets are especially volatile. BitShares also offers other derivatives such as bitCNY, bitEUR, bitGOLD and bitSILVER which can be very helpful in diversifying and keeping value. Happy trading!