I've had mine in the default target retirement funds of the provider (Fidelity / Empower / Vanguard) from different employers. After seeing how much of the fund is invested in bonds (10% for Vanguard) despite the long time until retirement, I'm looking at moving everything to VOO / VTSAX / VFIAX to have a more aggressive allocation in 100% equity.
Curious what others here have opted to do.