The shares of ON Semiconductor Corp. (ONNN - 9.25) are on pace to end the week about 4% higher, and could finish north of their 50-week moving average for the first Friday since mid-July. Furthermore, it looks like short-term options traders are expecting even more upside for the equity.

In the final hour of the session, ONNN has seen roughly 2,800 calls cross the tape -- about five times the norm. For comparison, fewer than 200 ONNN puts have changed hands.

Upon closer inspection, we find the at-the-money February 9 call at the heart of the action, with more than 2,500 contracts exchanged -- mostly at the ask price, hinting at buyer-driven volume. Currently, this option carries open interest of just 2,497 contracts, pointing to at least a few newly opened positions. By purchasing the 9-strike calls to open, the buyers are expecting ONNN to extend its recent climb north of $9 over the short term.

From a broader sentiment standpoint, today's preference for calls runs counter to the growing trend seen on the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX). In fact, the equity's put/call volume ratio of 0.43 registers in the 81st percentile of its annual range, implying that options speculators have bought to open ONNN puts over calls at a faster-than-usual pace during the past couple of weeks.

In late afternoon trading, ONNN has added 2% to explore the $9.25 region.