Very few people store cash under the bed. Most people know...

Very few people store cash under the bed. Most people know enough about shares to be able to buy an index fund or mutual fund if they don't want to buy individual share themselves. You can start with as little as $20 per month. 

Very few ordinary people can afford to invest in paintings or would want the hassle of buying, storing, insuring and selling them or of knowing what to buy.