If you have a reasonable ammount of money that you would like to save long-term and (potentially) remonetize 10+ years later on (for example for your retirement or whatever) then decide against playing the stock market (duh) or putting it in low interest bank accounts and buy the right stamps instead.
My dad is a passionate collector, but I have hardly any interst in collecting useless historical artefacts because I'm more interested in the future of humanity than its past. However even without any historical interest in the particular subject, stamps are an amazing thing to put your money into, because:
Few stamps ever fall significantly in value, some remain stagnant and most rise significantly over time. So having many rather than a few really valuable ones is good and in a timeframe of decades many individual stamps can easily double or triple their value.
They are very small, light and portable. Unlike most other art-objects you could potentially remonetize quickly. Much lighter than coins or anything else, really.
If you remonetize them, you don't pay extra taxes which you may have to pay for gains from playing the stock market. If there will be a tax on that at some Point in the future (which is unlikely for some reasons I won't get into), it can be easily avoided - illegally and probably legally as well.
You can remonetize them very, very quickly for a very good price by knowing the right person / auction house.
Unlike numbers on a bank account they are inflation proof.
No inheritance tax, your significant others will get all the dough if they remonetize it themselves.
The downsides are that you have to put some significant time into this topic to know what a good deal is, learn how the market and auction houses operate and to build a diverse or highly specialized and sought-after collection that is very likely to rise in value compared to other possible collections you could compile (which overall will almost certainly rise in value too, but maybe not as much as a collection you put some thought into).
Also you obviously need to keep them safe from theft and environmental hazards. (If you want to make the collection a one-time endeavor instead of an ongoing process, you can finish up your collection and put it in a small or medium safe deposit box in any bank.) Consider optimal storage conditions as well, since stamps are essentially made of fancy paper.
If none of this interests you, then at least take this advice: If you ever inherit a stamp collection, don't sell it on a flea market, inform yourself and sell it properly. Just recently a friend of my dad asked his advice on a collection he was about to sell for low double digits to learn that it was worth at least 20000$.
I wonder if Magic Cards (Specifically the Power Nine cards and Beta Dual Lands) are not a good investment? They have multiplied by about 10 in price over the last ten years. I've known people who had 300 Serra Angels, a terrible investment whose price decreased from 8 dollars to about 1 or less over the years.
Magic is both a collectible and a game, I don't know how that factors in expected value return.
Usually the top 0,3% (in future relative scarcity in Type1 and Legacy) increase steadily in price no matter what, top 1% unless they are reprinted (in w...
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.