When I like a fund, even if it starts to lag, I rarely sell it completely. Instead, I sell most of the position and leave a few shares behind.
That is one reason I probably have 20–30 funds with very small positions.
In my approach, I don't diversify for the sake of diversification. I prefer to concentrate in the funds that have demonstrated the strongest performance over recent weeks, months, and longer periods. As conditions change, I may rotate into different funds every few months.
The small residual positions help me keep those funds on my radar and make it easier to revisit them if they start performing well again.
One mistake I see investors make is becoming collectors of funds. Over time, they accumulate 10–15 or more meaningful positions, creating unnecessary complexity. In my view, that's too many. I prefer to keep the core portfolio focused on a small number of my highest-conviction holdings.
I went over all AQR funds and found out the best choices are QLENX,QNZNX,QRPNX,QMHNX
Right now it's QNZNX based on ST+LT.