Investors shifted their 401(k) plan allocations away from stocks to bonds and cash in September, according to an analysis by Alight, a retirement plan administrator — a behavior that could be financially perilous , depending on their rationale.

Overall account trading among 401(k) investors was low during the month, signaling that most people weren't actively moving money or trying to time the market , said Rob Austin, head of thought leadership at Alight.

"[But] when people did make trades, they moved from equities to fixed income," Austin said. "There's this flight to bonds, money market and stable value [funds]."

More from Fixed Income Strategies:

Stories for investors who are retired or are approaching retirement, and are interested in creating and managing a steady stream of

See Full Page