Significant options volume showed up on earnings day last week for Micron (MU). The computer memory chip producer was up nearly 5% on better than expected earnings. That’s likely why 75% of the 335,000 options that traded that day were calls. Call activity tends to correlate with bullish activity in the stock. Several of the larger blocks of trades were call ratio spreads, typically a professional-level strategy. The indication is that MU could be going quite a bit higher by May expiration.