According to morningstar's data, FZROX has 2500+ stocks and $2.5 billion in assets. That's about the same as Schwab's U.S. Broad Market ETF ("SCHB") which has $14 billion in assets.
https://www.morningstar.com/funds/xnas/fzrox/quote.htmlThe downside of only having 1 quarter of performance data (3-5 months) is that it's a total stock market fund. There isn't much experimental about that, and Fidelity has experience with this exact kind of fund.
But there is one surprise that will be interesting to track going forward. Which of the following total stock market ETFs/funds performed best in 2018 Q4?
Fidelity's FZROX (0.00% fee)?
Schwab's SCHB (0.03% fee)?
iShares' ITOT (0.03% fee)?
Vanguard's VTI (0.04% fee)?
I would expect their performance to line up in the same order as their expense ratios, but....
VTI and ITOT are tied: -14.20%
SCHB comes next: -14.30%
FZROX is last: -14.31%
The absolute performance isn't my point: the 0.11% gap in performance that can't be explained by a 0.04% difference in expense ratios. And although ITOT and VTI have different expenses (0.03%, 0.04%), they had identical performance.
I believe the mystery is actually solved easily: VTI and ITOT have ~3500 stocks, while SCHB and FZROX hold ~2500 stocks. So their difference in holdings (~1000 socks) impacted performance more than their expense ratios. And that holds even though all 4 have the goal of holding the broad US stock market.