Traders are favoring calls today on ON Semiconductor Corp. (ONNN - 7.11), with bullishly oriented option volume rising to double the usual daily level. So far, 2,074 calls have crossed the tape on ONNN, along with just 146 puts.

The day's most active strike is ONNN's November 7 call, where 1,998 contracts have been exchanged. Nearly all of these calls traded closer to the ask price, indicating they were purchased.

From a broader perspective, today's skew toward calls is part of a growing trend for ONNN. During the past 10 sessions, speculators on the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX) have bought to open 15.65 calls for every put on ONNN. This ratio arrives in the 69th annual percentile, pointing to a growing preference for bullish bets over bearish.

On the other hand, short interest on ONNN rose by roughly 13% over the most recent reporting period. With short interest and buy-to-open call volume rising in tandem, it's possible that bears are buying calls in order to hedge their bets on the semiconductor stock, rather than to speculate on future gains.

ONNN has emerged as a technical laggard lately, with the stock declining beneath pressure at its 10-week and 20-week moving averages since early June. However, the equity's slide seems to have tapered off near the $6.50 area, which could explain why shorts might be feeling a little anxious.