I would argue that the employee's current risk is greater than the stockholder's risk, since the stockholder generally has much more information about exactly what he is risking than the employee does -- and a greater legal right to that information. The average employee has no legal right to information about the health of the company where he's employed. He has to take the risk that the company isn't simply going to collapse out from under him leaving him with no income and a, best case, several week or month job search.

So what about the case of a worker cooperative economy? Where would the risk come from in a worker cooperative (beyond the normal risk an employee assumes)? Capital financing, which could still be done by debt or by crowd sourcing. In the case of debt, the risk depends on how we structure the companies. If they are structured as limited liability corporations, where only the property of the company can stand as collateral for debt, then the employee owner doesn't risk anymore than he does joining any other corporation. The difference is he has a legal right to complete information about the company's health and a voice in picking its direction.

He actually take substantially less risk in a worker cooperative (where employment means ownership is granted as a part of salary as opposed to being required to buy shares) than with a normal corporation. And he stands to reap the full benefits.

Free market socialism (i.e. a large UBI + single payer healthcare + low regulation) would largely mitigate that risk aversion, especially when combined with low levels of personal debt, since if you fail you can always count on decent healthcare and the UBI check.

Of course Mondragon in spain is different you have to Ante up