Well yeah with any position that youre going to hold for two years (especially one thats in a coin that just came into being a few months ago), price fluctuation is a danger. That said, you can actually take a pretty significant hit on price and still break even. At least in theory, over two years you should break even even if the price of steem goes down 75%.
THat said, one of the interesting things about the "bond" (and, in fact, one of the things bonds are used for in real life) is that its a hedge against the price of steem going down. So, for example, lets say i put $100 in Steem Power and $100 in SBD. If the steem power drops in price by 50%, the steem value of my SBD doubles ($1 now buys twice as much steem)