Would I Invest in BITCOINS ?

If I invest in something it has to have some substance. BITCOINS is backed by nothing. Ziltch not a thing except those who are willing to exchange it for something. Why would anyone want to ? The Paper Dollar at least has some substance but in my mind it is only to be used to purchase something that has value--substance ! Land, Gold, a business, paintings you know what I mean. Todays news is saying what was the largest exchange for bitcoins website at one time is possibly down for the count. Heads up !!