Hi. I want to invest in maybe 30/40 alts. I don't have a hardware wallet. Where do you recommend to hold them? Exchanges? I know they are not the safest option, but one wallet for each coin is not very practical. Also, what is the way you recommend to pay lower fees to buy this alts from BTC? Thanks guys....
Jaxx.io interfaces with ~10 of the larger cryptocurrencies. You hold the private keys. It doesn't have any blatant vulnerabilities. But it also isn't the most secure desktop wallet because it cannot be encrypted with a strong passphrase. There aren't many wallets that can hold dozens of coins, though. That's probably as good as it gets.
The only way to pay lower fees is to use limit orders instead of market orders. They tend to be cheaper (or in some cases, free, as on GDAX).