Company Stock in 401(K) Plans

Abstract

Investors in 401(k) plans violate basic principles of diversification by holding a significant fraction of their savings in the form of their employers' equity. This paper characterizes investors' active changes to their company stock investment over time by analyzing new inflows and transfers. Investors seem to base active changes on salient information, paying attention to past returns, volatility, and business performance. Past returns, over a three-year horizon, predict higher inflow allocations and transfers, whereas volatility and business performance only have a weak effect. The sensitivity to past returns is asymmetric, with investors reacting more strongly to positive and above - S&P500 returns.