Spelling out the difference between investing and trading
There is a thin line between trading and investing. A veteran adviser spells out what differentiates the two approaches

Investors are often thrown glib phrases like "Let winners run!" or "Kill dogs early!" or "Markets can remain irrational longer than you can remain solvent!" There are too many to list and whenever I hear one of these phrases I try to mentally file them into one of two investment categories: Investing or Trading. But what is the difference between trading and investing, or between a trader and an investor? There is, of course, no exact definition but here are some thoughts that might help clarify:
If you are going in because something has an attractive value, most likely you are investing. Traders often do not care much whether something is cheap or expensive.
If you are shorting one stock against another long stock, you are most likely betting on a "reversion to the mean" - in other words you are a trader betting that the value spread between the two stocks will revert to some previous average level. Investors usually do not care about the value spread between two stocks.