The phrase "outsized gains" refers to unusually large or significant profits or increases. It means that something or someone has achieved much larger or greater success than expected or compared to others. Full definition
I basically missed out on making outsized gains in everything because I was so concentrated on my career. (financialsamurai.com)
This recent turn of events favoring international equities over U.S. equities could point to the early makings of a mean - reversion following years of outsized gains for U.S. equities. (etf.com)
Our base of assets and earnings is now far too large for us to make outsized gains in the future. (alephblog.com)