Call buying accelerated on Tesla Motors Inc (NASDAQ:TSLA - 33.75) last week, according to volume data from the major options exchanges. During the past five days, traders on the International Securities Exchange (ISE) and Chicago Board Options Exchange (CBOE) bought to open 2,576 calls on the electric automaker, easily outstripping the 253 puts that were purchased. TSLA's five-day ISE/CBOE call/put volume ratio of 10.18 confirms that bullish bets on the stock were more than 10 times as popular as their bearish counterparts.

As a result, the security's cumulative 10-day call/put volume ratio on the ISE, CBOE, and NASDAQ OMX PHLX (PHLX) has been creeping higher. A week ago, on Dec. 17, the ratio was resting at 1.23; today, it's ramped all the way up to 2.23. In other words, calls bought to open have more than doubled puts on these three exchanges during the past couple of weeks.

Despite the recent uptick, bullish speculation has yet to hit peak levels on TSLA. That call/put volume ratio of 2.23 arrives in just the 46th percentile of its annual range, pointing to a fairly typical level of call buying of late.

TSLA has trekked steadily higher from its late-October lows near $27, but the stock has been consolidating some gains during the past couple of weeks. The shares are now testing support near the $33-$33.50 area, which has provided a technical floor since the end of November.