LAS VEGAS, July 30 -- The $87 million question on Wednesday belonged to Patrick Dumont. His company's quarterly earnings landed nearly 25% below what Wall Street had expected. Within hours, the board he chairs authorized $6 billion to repurchase shares of Las Vegas Sands Corp., a bet that the stock is worth far more than one bad quarter suggests.

Second-quarter net income fell to $373 million, or 53 cents per diluted share, from $519 million in the same period a year earlier. Adjusted earnings of 59 cents per share missed the analyst consensus of 76 cents. Revenue of $3.15 billion came in roughly 5% below the $3.31 billion Wall Street had projected, as Las Vegas Sands disclosed in its official second-quarter results. Shares fell more tha...