Both alts and BTC will give a good profit in future. But I think alts will be more profitable than BTC because some alts in a big dip and surly price will increase atleast 10 times in a bull run. In last bull run also btc price increased about 3 times but some good altcoin's price increased about 10-15 times some increased about 50 times. But we must find good altcoins from heavy researches.