Three soaring ASX 300 shares just upgraded by leading brokers

The S&P/ASX 300 Index (ASX: XKO) has gained more than 17% over the past year, but the three ASX 300 shares we’ll look at below have all surged by far more.

Well, two of them have.

The third company only began trading on the ASX on 23 September after being spun off…