A B C D G H 1 On july 26 2018, facebook announced weaker-than expected revenue and dissapointing 2 growth in its number of daily active users. the stock pluged 19% from $217.50 to $176.26 in 3 just one day, wiping out over $119 billion of the firm's total market value and reducing 4 founder mark zuckerbeg's personal fortune by almost 16 billion of the firm's total market 5 value and reducing founder Mark Zuckerbeg's personal fortune by almost $16 billion. 6 Imagine that an investor purchased 100 shares of the stock on july 25, using 50% margin. the 7 cost of 100 pares was $21,750. The investor put up half of that ($10,875) in equity and took 8 out a margin loan in the same amount. One day later, those shafes were worth $17,626, 9 leaving the investor just $6,751 ($17,626-$10,875) in equity. Thus, the investor's one-day 10 rate of return was ($6,751 - $10,875) = 37.9%