On Tuesday, Corning (GLW.US) opened lower and continued to decline, falling nearly 20% as of press time, with a drop of over 54% since July.

The company reported its second-quarter results, with core sales of $4.74 billion, up 17% year-over-year and exceeding expectations by about 2.3%. However, the Q3 guidance fell far short of expectations, with core sales guidance of $4.9-5.0 billion, where the high end only matched estimates. The implied sequential growth rate in the guidance dropped sharply from 9% to 3-6%.

Market disappointment centered primarily on the performance guidance. According to data, analysts had expected Corning to report third-quarter sales of $4.99 billion and earnings per share of $0.85.