If someone has $50 invested in AMBS and it is 100% of their portfolio and that $50 is important to them then they could also be dangerous and biased according to your argument. So, unless you know what amount is detrimental or too much for someone I think it's crazy for you to accuse someone that has $300k or any amount biased and dangerous based purely on the amount they have invested. You don't know their net worth, so how can you know what they can afford to lose? I wish I could afford to invest as much but I can't. I do know people that could and it would not impact them to lose $300k. I would never assume anyone is biased or a dangerous investor because they have more than my comfort level invested.