Your odds of winning are proportional to the amount you deposit. This means large depositors have a higher chance of winning (and also contribute more interest to the prize). However, these large depositors give smaller depositors a chance to win 2x-40x their deposited value.
A community member (@mcoso) has made a Luckiest Winners Leader board showcasing all the lucky fish (someone with a small deposit).
Here are some examples of depositors that have received 1.2x to 599x their deposits.
$10,336 deposited → $26,523 won
$14,700 deposited → $57,459 won
$26,578 deposited → $33,763 won
Large depositors have a higher chance to win but the amount they win is much smaller proportional to their deposits.