He should pay a reasonable wage, charge a fair price, and be decently restrained in the way he spends his profits (which, the shrewd Islamic economist points out, ought to be good for investment and healthy counter-inflationary).

ECONOMIST: A survey of Islam and the west

You must identify the right business or company to invest in, and it must be purchased at a fair or reasonable value (price).

FORBES: Connect

The pause gives the markets the opportunity to attract new trading interest in an affected stock, establish a reasonable market price, and resume trading in a fair and orderly fashion.

FORBES: Proposal to Address Extraordinary Market Volatility