There are some good economic reasons no one created an Ebola vaccine – yet. Now multiple companies, including Johnson & Johnson, are racing to produce a cure. The business rationale changed in part due to the size of the outbreak itself, but also an increasingly interested market and potential payday. Plus: New regulations aimed at preventing another housing crisis have been finalized, only they don’t include a down payment requirement. Financial experts think homeowners should put down 20 percent to be safe, but where did that number come from in the first place? Also: Seemingly out of nowhere in 1979, the Hunt brothers attempted to corner the silver market, pushing up prices almost 1,000 percent as they bought rights to nearly half of the silver in the open market. But when the commodities markets responded by changing the rules for margin trading, they went bust. Following the death of Nelson Bunker Hunt on Tuesday, Oct. 21, we look at why this strange bubble can’t really happen again.