Short answers, pulled from the story.
The Nasdaq exchange introduced the Nasdaq-100 on the 31st of January 1985 with a base price of 250 points. This index originally included 100 of the largest non-financial companies listed on the exchange.
Companies must be listed exclusively on Nasdaq Global Select or Global Market tiers and maintain an average daily trading volume of at least 200,000 shares. Firms are required to file quarterly and annual reports without delay and cannot be in bankruptcy proceedings.
The index reached above 4,700 during the dot-com bubble peak in 2000 before falling 78% within two years as the bubble burst. A gradual recovery followed, hitting an intraday high of 2,239.51 on the 31st of October 2007.
Investors access the Nasdaq-100 through the Invesco QQQ exchange-traded fund which has traded under ticker symbol QQQ since the 23rd of March 2011. Derivatives markets trade futures contracts based on the index code NDX or ND with smaller E-mini versions using the code NQ.
Nasdaq reviews and updates the index components every December based on market performance and corporate actions like mergers or delistings. Changes appear publicly via press releases five business days before taking effect.