Here is the explanation how the distribution works "behind the scenes":
1) For processing, the contract keeps track of all token holders and indices in an array
2) Depending on the transaction size, each transaction handles a particular number of users (bigger token transactions can process more users, since the gas will still be proportionally less than the value of the tokens)
3) The token follows the Dividend-Paying Token Standard, which ensures that all mTSLA (a tokenized version of stock) contract profits will be distributed evenly among token holders
4) When a holder is processed, the contract examines how many withdrawable dividends they have. If that number is greater than the minimal threshold for auto-claims, either claims those dividends for mTSLA or buys back tokens for them.