In the case of real estate, use one of the bubble states as an example. Let's pick Florida. Using ballpark numbers, Florida has about 16 million residents. Of those, perhaps 10 million are home owners. At any given time, perhaps 5 percent of homes are for sale. So, at any given time, 500K homes are for sale. Some people will be planning on moving out of the State but that will be offset by people wanting to move into the State. The majority will never-the-less be, in-State sellers selling to in-State buyers.
Now, If suddenly from around the world 100K speculators descend upon the state, there will suddenly be far more buyers that sellers and the market will bid the prices up. Prices being bid up will force normal buyers sitting on the fence to buy and will attract new speculators.
So, this is a very simplistic example of how just a few speculators can drive a market bonkers.
The oil futures market is very different from the real estate market.
For instance, the world’s stockpile of houses isn’t burnt up and replaced every day.
Unless you’re a major oil producing nation — it simply isn’t possible to hoard a significant supply of oil. Speculators aren’t hoarding the stuff — they’re simply betting on the future prices.