The G fund’s return formula often has been cited as a very valuable benefit—the other is the TSP’s very low administrative fees in comparison with other investment options such as mutual funds—that is available only to TSP participants, one reason it is now attracting attention. One result is that the G fund traditionally has been the largest of the TSP’s funds, currently holding about 43 percent of the total on investment. In the early years after the TSP was created in the late 1980s, there were restrictions against investing in funds other than the G fund. While those restrictions were lifted many years ago, the G fund’s predominance has continued. Nine-tenths of TSP investors have at least some of their money in it and more than four-tenths have all of their money in it. The fund is especially popular among employees late in their careers and among retirees, who are seeking stability in their investments because by definition the G fund cannot lose value. On the other hand, the youngest employees also have disproportionately high investment levels in the G fund. In many cases, that’s because the G fund is the default fund for those newly hired; they have automatic investments of 3 percent of salary taken out unless they make a different election. Many of them never elect a different allotment, with the result that they may be investing too conservatively for their age. That was the main reason behind a change enacted last year to make the default fund the lifecycle fund appropriate for the person’s age. However, that will apply only to those hired after implementing rules are finalized, which is expected to be in the fall.