Thank you, Coolhand! Over the past few weeks, I've been overloading my frail brain trying to understand why F Fund was moving the way it was, and I wasn't making any headway.
It was easy to absorb the base facts: The F Fund is invested in the Barclays U.S. Debt Index Fund, which tracks the Lehman Brothers U.S. Aggregate (LBA) Index, and does so by purchasing shares of the Barclay's U.S. Debt Fund Index "E", which in turn holds shares of the Barclay's U.S. Debt Index Master Fund. The F Fund is invested in investment-grade fixed-income securities with maturities of more than one year, with a break-out of approximately 45% asset-backed securities, 35% government or government related securities, and 20% credit.
And I understand that in today's financial market, the 20% credit could fluctuate, and even the 45% asset-backed securities are only worth what current fair market value says they are. But I didn't think anyone would be doing a mark to market on them to account for some of the wild swings we're seeing.
So I read your linked article with great interest, especially the last part:
"Finally, this must be an embarassment to Barclays, which runs iShares. They have a large vested interest in making sure that investors don't come to view ETFs as having this type of NAV discount risk.
"This is an opportunity certainly for longer-term fixed-income investors (buying "the market" at a large discount), but it is certainly potentially an opportunity for a trader. Yes, in this crazy market, an anomaly that might ordinarily not persist for long could end up taking a while to reverse, but this one, given the redemption process, seems unlikely to endure.
"Disclosure: Long AGG"
Finally something that makes sense to me and explains what I'm seeing! And confirms something I was thinking of doing with my TSP account as well! Thanks again!

Lady