Shares of Cooper Tire & Rubber Company tumbled 10% pre-market on Monday as the company reported first-quarter earnings that missed analyst expectations, and said it expects a "choppy" business environment in the coming year. The company had net income of $8.29 million in the quarter, down from $30.56 million a year ago. Per-share earnings were 16 cents, versus 57 cents a year ago, and missing the FactSet consensus of 57 cents. Revenues totaled $601.5 million, down 6.5% from $643 million a year ago. The company blamed "weaker volume and higher manufacturing costs" in a release, and said "we expect our performance to be choppy in the months ahead." Cooper's tax rate in Q1 was 27.8%, vs. 30.7% last year, and the company said it expects capex of $200-220 million in 2018, and an operating profit margin of 9-11% in the second half. The stock has lost 24% for the year to date, while the S&P 500 [s:spx] has been flat in that time period.