You cannot have both safe and high return at the same time (if such a thing existed, we would all rush in and spoil your party). Investments give you winning returns over time precisely because they are not safe in the short term.
BLNDX's stated goal is to match total world equity funds. It's happened to do well recently as it moved half to cash. However, anything active enough to move half its funds in to cash is overwhelmingly likely to miss out in the long run by leaving you out of the market when you should be back in. This looks like a classic terrible product for the customer (an outrageously expensive 1.28% expense ratio) and if it can move so much in and out of cash, will leave with with a tax bill too.
The way to turn the tables on the Wall Street casino is to avoid these games where they are making all kinds of complex bets and instead stick with the low fee index funds like you are already in. Then, you become "the house", winning as the market moves up over time while the folks that got fooled by Wall Street's slick marketing are all busy betting against the pros.
So relax, your S&P 500 fund is a fine place to be over time.