Curious what you mean by investing. Like financial investments? Infrastructure? Or in the playing squad?
I think we have used some of the money to invest in infrastructure, with the pitch upgrade reportedly saving us 100k per year, and opening up possible revenue streams such as internationals and pre season friendlies.
Investing in the playing side is tricky. For the youth side of things, maybe we are investing? But we won't know if that pays of for years. As far as the first team goes, look at Aberdeen, hibs and united, their wage bills are multiples of ours, and I don't think it has made them protortionally better than us. It does look like we're trying to purchase "assets" with the likes of Tierney and Danzaki. Chances are that was the idea with Shields, Mahon, and Woolery too, maybe even Kelly.
On the financial side, f**k knows, not my area. However, considering how we looked after ourselves with insurance and the like, it seems like we have our heads screwed on in that department. I don't know what clubs tend to do with their cash reserves, but I think we have expertise in that area on our board.