Recent articles have generated considerable discussion on the site about the cost incurred by those who try to time the market with frequent buying and selling of their TSP funds. A few readers contend that it costs the TSP considerably more to balance the lifecycle funds than the costs incurred by those trading frequently. Does anyone know the actual costs of the lifecycle fund rebalancing and how do these costs compare to the costs created by those frequently trading the I fund?

Out of a few million Thrift Savings Plan participants, there are several thousand who trade their funds on a frequent basis. This activity is costing a few million dollars a year in additional expenses. The TSP is considering a recommendation to limit the number of TSP trades that a participant could make during a month.