Shares of iQIYI (NASDAQ: IQ) had a bad market day today. Share prices fell as much as 14% in the afternoon, recovering to a 13.3% drop by the closing bell. There was no obvious reason for this plunge, other than the young stock's heaping reserves of volatility making another appearance.The so-called Netflix (NASDAQ: NFLX) of China -- and Chinese business partner to that streaming video giant -- had no news to speak of today.