Every Monday in its weekly edition, "IBD" publishes a list of 50 stocks that are most attractive based on earnings, stock price performance, and other criteria used in the CAN SLIM strategy. The IBD 50 Index is the flagship US stock market benchmark published by the Investor’s Business Daily, similar to how FTSE 100 was to the Financial Times. The index is based on the CAN SLIM methodology invented by the newspaper’s founder William O’Neil, and the list of its constituents is published every Monday. Later it becomes the basis for an exchange-traded fund (ETF) called the Innovator IBD 50 ETF (Ticker: FFTY), which is also rebalanced weekly. In July 2009, an editorial in "Investor's Business Daily" claimed that physicist Stephen Hawking "wouldn't have a chance in the U.K., where the [British] National Health Service (NHS) would say the life of this brilliant man, because of his physical handicaps, is essentially worthless." Hawking was British, lived in the United Kingdom nearly all of his life, and received his medical care from the NHS. "IBD" later removed the editorial's reference to Hawking in its online version and appended an "Editor's Note" which said, "This version corrects the original editorial which implied that physicist Stephen Hawking, a professor at the University of Cambridge, did not live in the UK." Hawking himself responded, "I wouldn't be here today if it were not for the NHS. I have received a large amount of high-quality treatment without which I would not have survived."