Shares of Rambus (RMBS 1.91%) are down 19.2% as of 2:45 p.m. ET Tuesday after the chip interface technologies specialist announced weaker-than-expected quarterly results.

Rambus was pleased with its "strong" quarter

Rambus' fourth-quarter 2023 revenue fell slightly on a year-over-year basis to $122.2 million, as a 67% increase in royalties revenue (to $52.4 million) was more than offset by declines in product (down 20% to $53.7 million) and contract revenue (down 32.4% to $16.1 million). On the bottom line -- excluding non-recurring items such as stock-based compensation and a one-time gain on the sale of an equity investment -- that translated to non-GAAP (adjusted) net income of $41 million, or roughly $0.37 per share. Analysts, on average, were expecting earnings of $0.45 per share on revenue closer to $140 million.

Licensing billings for the quarter were up around 3% year over year to $66.2 million.

Rambus CEO Luc Seraphin noted Rambus' earnings and revenue arrived near the high end of the company's guidance, calling it a "strong fourth quarter ... that outpaced the overall semiconductor market."

"With our focus on high-performance solutions for the data center and AI, we are well positioned to drive the long-term profitable growth of the company and consistently return value to our stockholders," Seraphin added.

What's next for Rambus shareholders?

Rambus' current guidance for the first quarter of 2024 assumes product revenue $47 million to $53 million, contract and other revenue of $17 million to $23 million, and licensing billings of $59 million to $65 million.

In the end, though, Rambus was pleased with its quarter as it outpaced the growth of the broader semiconductor market, Wall Street was obviously unamused by the miss relative to expectations. Rambus shares are responding in kind.