Transaction costs are investment expenses that reduce investment income before deductions for administrative expenses and are not included in the administrative expense ratio. (See the Thrift Savings Plan Statement of Changes in Net Assets Available for Plan Benefits portion of the Plan's financial statement.) Transaction costs of $13.8 million reduced the I Fund return by 8 basis points (or .08%) in 2006; net administrative expenses only reduced participants' returns by 3 basis points (.03%) in 2006.
Frequent trading also increases the cash the investment manager must hold to meet redemptions, which leads to a greater chance of differences in performance from the indexes tracked by the funds. It is the goal of the TSP to keep this "tracking error" as low as possible since the funds are designed to mimic their respective indexes.
The TSP is a huge plan with $235 billion in assets. Why are transaction costs of $15 million a problem?
As indicated in Question 8, transfer costs affect the returns of the funds. For example, the I Fund's transaction costs in 2006 decreased the I Fund's return by 8 basis points or .08%. The cost of administering the TSP program was only 3 basis points (.03%) in 2006. The Board is charged with keeping TSP expenses low for all participants. We have determined that trading restrictions will result in a significant expense reduction for TSP participants.