The idea of "hedging" Bitcoin by buying altcoins is ridiculous - it's the exact opposite of hedging, as altcoins are more risky than bitcoin. Hedging is done to reduce risk by taking a position that is opposite to an existing position.

The only way to hedge bitcoin that you own is to shortsell bitcoin. To a limited extent, a person could buy derivative contracts to lock a sell price, but the bitcoin ecosystem does not have a particularly good system for this.