I wasn't aware you're not in the US. If your country has high capital gains taxes compared to income taxes, the balance might be different in the US. However, stamps and other collectibles have many problems:

-- Stamps can get stolen, lost, or burned in a fire. It's hard for this to happen to stocks (unless you're behind the times and have them as a pile of paper certificates)

-- If you buy a type of collectibles that you're actually interested in, your desire to keep a co llection of something you're interested in may lead to poor decision-making on a financial level

-- When buying stamps and other collectibles, you generally have to pay retail prices, and when you sell them, you only get wholesale prices. And you can sell a stock any time; selling a collectible is a big deal and takes effort.

Also, I find it very doubtful that stamps aren't subject to inheritance or estate taxes.