alt Hacker NewsReminder that VTSAX, VTBLX and VTIAX are all you need. 50/25/25 split, as per Bogleheads. (FXAIX, FXNAX, FSPSX if your acct is on Fidelity).
(Also a reminder that target funds are expensive and will sometimes be over-allocated towards hot industries depending on the retirement year "target".)
Reminder that Fidelity back in March gave notice that they no longer would limit the largest holdings to 5% (e.g., in FITLX). So even if you noticed, and if you wanted to control your own risk, you'd have to sell your holdings, a taxable event.
So index funds are no solution, unfortunately. They'll lose deposits if they sit on the sidelines (as people compare 8% returns to 15+%), so their incentives are not aligned with avoiding the bubble.
The perfect scam, er virus, lives well enough to spread but doesn't kill quickly.