The TSP F Fund is a U.S. bond index fund. The fund uses a “passive management” (indexing) investment approach, designed to match the performance of the Barclays Capital U.S. Aggregate Bond Index, a broad index representing the U.S. bond market. The F Fund provides broad exposure to U.S. investment grade bonds. It invests about 30 percent in corporate bonds and 70 percent in U.S. government bonds of all maturities.
As of this writing, the Barclays U.S. Aggregate Index contains over 7,800 bonds. Its yield to maturity hovers around 2.3%, and the average coupon is 4.1%. The average maturity is 7.3 years, and the average duration is 5.1 years. Funds tracking the Barclays Aggregate index typically sample the index and hold fewer bonds (less than 5,000), but all important risk factors and other characteristics should track the index closely.
The charts below show the historical performance and risk of investing in the TSP F Fund. As of 7/19/2018, the fund has a compound annual growth rate of 6.0%, annualized standard deviation of 3.8%, and Sharpe Ratio of 0.37. An initial investment of $1,000 on 8/31/1990 would today be worth $5,082:
The chart below shows the historical drawdowns for the TSP F Fund. The worst drawdown since inception was -6.6%:
There are many other mutual funds and ETFs tracking the same index used by the F Fund (the Barclays Aggregate Bond Index). Popular examples include Vanguard's Total Bond Market Index Fund (VBMFX), Vanguard Total Bond Market ETF (BND), and iShares Barclays Aggregate Bond ETF (AGG). Many bond investors consider these funds to be their core bond holding (since they invest in all segments and maturities of the fixed income market).
Bond investors (including investors in the F Fund) are subject to several types of risk, including inflation risk, interest-rate increases, and a potential default by the issuer of one or more of the bonds in the portfolio. Lets take a look at these in greater detail:
Although there are several types of risks associated with the F Fund, the overall risk is relatively low, because the F Fund holds a very diversified portfolio of high grade (investment grade) bonds. F Fund investors have the opportunity to earn higher long-term returns compared to investors in short-term securities such as the TSP G Fund.
The prices of bonds and stocks don't always move in tandem. In fact, investment grade bonds are often uncorrelated or negatively correlated to stocks (bonds zig when stocks zag, and vice versa). A retirement portfolio that contains an allocation to bond funds like the TSP F Fund, in addition to stock funds like the TSP C, I, and S funds, will typically be less volatile than one that contains only stock funds.
In our tactical asset allocation strategies, we dynamically allocate a portion of investable assets to the TSP F Fund, based on the prevailing market conditions.
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