Over 75% of my equities portfolio is in the trusty VTSAX. I love it. But the other 25% are sector funds. I’ve got one healthcare fund, one tech ETF, and one gold fund. One of those has been an absolute rockstar for several years since 2009 with 27% return this year, blowing VTSAX (19.96 ytd)out of the water. Gold hasn’t gone anywhere (6%return this year) The last one I have is a new fund established in 2016, early days still so the jury is out but so far with a 33% return ytd.
I would say look for a growth fund that had at least a 10-15 year track record, and research it before you invest. I’m partial to healthcare and tech :)