Renting out GPUs

I’m really into home compute and running local LLMs, the benefits I get from them outweigh any cloud service, but cost is still an issue. Is there any way to rent out GPUs with no high uptime for example by joining distrubuted training runs and getting paid for it, I couldn’t find anything but shouldn’t something like this exist? 50% of the day my GPUs aren’t doing anything, that’s just wasted compute / money. I’m also adamant on upgrading home cluster cause GPU prices are high and well, it is cheaper to buy a Claude subscription. If there is any way I can rent out my GPUs though, it would make life alot greater. Thanks alot for your responses!