No, it's not. If someone has no stake then they have little incentive to be right or not. And in the long term, it's better for them to try to be right becaus

No, it's not. If someone has no stake then they have little incentive to be right or not. And in the long term, it's better for them to try to be right because they can brag about their historical accuracy when making future predictions. But for people that have some risk in Tesla (this firm's ETF is over 10% TSLA), then they have an incentive to pump the price up, even if it means lying. If they can pump the price they benefit. There is no reason why their advice should be trusted if their advice is toward the direction that obviously benefits them. Now, if someone had 10% of their money long TSLA and they said the price was going to fall, then I would probably trust them because that advice isn't directly benefiting them (or I'd be very suspicious that they had some other scheme going on).