[jcfrei]

Jane street and others are essentially market makers. Which means in one way or another they get paid for providing liquidity. They have a different pay off profile from hedge funds, retail traders or mutual funds which usually make a directional bet. For example by having exclusive order flows (for example from robinhood traders), lower trading fees (often rebates), access to better execution (via dark pools), cheaper financing (for leveraged trades), tighter spreads in OTC deals, etc.

[jamespattn]

So is the idea that their quant researchers spend all their time finding alpha just a front/recruitment driver rather than the reality of what a quant researcher would typically do day-to-day to actually increase PnL?

[jcfrei]

All the examples I gave are a precondition to even take part in the market making game. Your actual market share and profitability within the space is then still determined by the quality of your models, execution, tech stack, market access etc. for which you need good quants, traders and also lawyers (for tax and offshore structuring).