"I was a stock broker once. I think there is an absolute place for market investments. But they should never be the basis of one's retirement. They should be an additional piece on top of a basic, secure, guaranteed retirement benefit"

This quote by Barbara Boxer suggests that while market investments can be advantageous, they need to not be the sole source of retirement income. Rather, she suggests having a protected, guaranteed retirement advantage as the structure of one's retirement plan. This is likely due to the fact that stock markets can be unforeseeable and unstable, and relying exclusively on them for retirement earnings could be risky. Fighter's experience as a stock broker most likely provided her insight into the prospective risks of counting on the stock exchange for retirement earnings. She is suggesting that having a safe, surefire retirement advantage is the best way to guarantee financial security in retirement.