For instance, if you buy a bond, you run the risk of the borrower defaulting or being repaid with debased money. As a stock investor, you face the risk that the company's business model will not live up to expectations, or that it, at the extreme, will go bankrupt. In an unhampered financial market, prices are formed for these and other risk factors.
For instance, a bond with a high default risk will typically carry a high yield. The same goes for debt denominated in an unsound currency. Stocks of companies that are deemed risky tend to trade at a lower valuation level than those considered low risk. All these risk premiums, if determined in the unhampered market, constitute a portion of an asset's price, be it a bond or a share. They play a vital role in the way capital is allocated in an economy.