United States Steel is upbeat about its first quarter, telling investors that earnings will be far better than expected because of skyrocketing steel prices. But Wall Street wasn’t buying all the good news Monday.

U.S. Steel (ticker: X) stock is down 5% in midday trading. Last week, though, shares rose 33%, pushing year-to-date gains from 8% to more than 44%. What’s more, the stock rose more than 8% Friday after management provided its initial look into the first quarter.

U.S. Steel expects to generate about $620 million in quarterly Ebitda, or earnings before interest, taxes, depreciation and amortization. Coming into last week, Wall Street was projecting closer to $500 million in quarterly Ebitda.

Three months ago, the Street projected just $200 million in Ebitda, and the company generated less than $100 million in Ebitda in the first quarter of 2020.

Steel prices are responsible for the reversal in fortune. Prices for hot-rolled steel coil, a key steel benchmark, are at about $1,260 a ton, up more than 25% year to date and up about 120% year over year.

Commodity-based companies are often leveraged proxies on commodity prices. U.S. Steel stock, for instance, is up more than 300% over the past year, far better than the gain in steel prices. Commodity company sales are tied to commodity prices. But commodity-producing companies also have fixed costs, which means earnings and free cash flow grow faster than underlying commodity prices.