New Delhi, Sept. 23 -- Even an absolute novice in the stock market understands what a 'buy' or 'sell' rating given by a research firm means. But 'hold'? That's not quite as intuitive, is it? The real question is: Is it even rational? Think about it-if a security is not worth buying today, why is it worth holding?

The whole construct of a 'hold' rating is to hide from us the fact that we are being irrational by putting a covert premium on something precisely because we are already holding it.

This irrationality arises out of something called the endowment bias. Anything that belongs to us automatically has higher value for us. Surprisingly, this holds true even for mundane objects.

A seminal study on the 'endowment effect' was carried o...