The U.S. tech giant Apple saw its stock price plunging more than 9 percent in early trading on Thursday after the company issued lower guidance for fiscal 2019 first quarter.

In a letter to investors from CEO Tim Cook on Wednesday, the company lowered revenue guidance to 84 billion U.S. dollars, down from the 89-93 billion dollars range it had previously projected.

The gross margin stood at approximately 38 percent, according to the letter, also lower than previous estimate.

Apple attributed the lowered guidance to four main factors, namely the timing of iPhone launches, a strong U.S. dollar, constrained sales of products including Apple Watch Series 4 and iPad Pro among others, and economic weakness in some emerging markets.

Cook also said in the letter that fewer carrier subsidies, price increases based on the strength of the U.S. dollar and cheaper battery replacements caused the weak iPhone upgrades for the quarter.

Apple shares traded as low as 142.81 dollars apiece, or nearly 10 percent lower on Thursday, registering a 52-week low. The company's stock price hit 52-week high three months ago at 233.47 dollars apiece.