U.S. Steel Corp.’s stock X, +0.98% soared 27% in premarket trade Monday, after the company rejected an unsolicited, $7.3 billion takeover bid from Cleveland-Cliffs Inc. that would have reshaped America’s steel industry. Cleveland-Cliffs’ stock CLF, -0.07% was down 2.6%. The latter on Sunday made public a previously private offer of $17.50 a share in cash and 1.023 shares of Cliffs’ stock for U.S. Steel, or a 43% premium based on Friday’s closing stock price and valuing the company at about $7.25 billion. Cliffs’s offer was rejected Sunday by U.S. Steel’s board, which called the proposal “unreasonable.” But the board acknowledged the receipt of a number of offers for parts or all of the company and said it was reviewing its strategic options. U.S. Steel’s stock is down 9% in the year to date, while the S&P 500 SPX, -0.11% has gained 16%.