What do you mean by "keep an amount of stock and provide for more later on when the initial has been taken"? And also what does "otc" mean?
Thanks
Don't hold too much crypto, especially on online wallets.
It's fast and easy to replenish stock, there's not a great need to keep buying more of you don't have the finances for it until your initial has dropped by quite a bit.
Otc is over the counter trading (ie getting an entity to trade with you at a set price rather than doing a market buy). It just means don't buy off exchanges, find other sources as they should be more reliable (especially if you have multiple).