Retirement investors made safe bets in August, according to Alight Solutions’ 401(k) Index, quietly moving their nest egg savings into fixed-income options from equities. The cautious mood was palpable. Trading levels in retirement accounts were eerily quiet with no above-normal trading days last month, per the index. When investors in 401(k)s did make moves, they shifted from large and small US equity funds and company stock into more conservative bonds and, to a smaller degree, money market funds and e ...