In 2013 i got in on the multipool altcoin mining game. I pointed miners towards the most profitable coin (at that time it was often LTC or DOGE). I would then sell back in for BTC and use profits to buy more mining rigs. When the BTC price ran up to ~1300 and the plummeted back down, a ton of new miners came onto the scene at the same time (more competition) making mining no longer profitable. I turned off my 30 GPU's and forgot about crytpo for a little while. Moral of the story, if I had just held all that LTC that was mined, or BTC that was exchanged for fiat to buy more miners i'd be sitting pretty. My reccomendation, mine as a hobby but if you're interested in investing serious capital, spend your time researching interesting projects and just speculate on them (my favorite site for ranking projects is coingecko.com), buy and hold something you beleive in. Mining is a lot of fun and I learned so much about crypto, but i'd only reccomend it as a hobby.