Geron (P/C Chart, news, volatility) saw a big move last Friday on news the FDA cleared the way for the company’s embryonic stem cell-based therapy clinical trials. Today, shares are up a dime to $8 and a new 52-week high. 24K calls traded. Feb 7.5 and Feb 10 calls are the most actives, with 17,700 traded ahead of an important Feb 9 presentation at the BIO-CEO conference. ISEE Sentiment data says 66 percent of the calls traded on the ISE are opening customer buy orders.

Barclay’s Launches Exchange-Traded Notes Tied to VIX

CMS Energy (P/C Chart, news, volatility) is seeing 19x normal volume today, as shares trade nearly flat at 11.83. Bulk of the volume was an institutional buyer of 3100 Jan-10 10 puts for $1.175 tied to shares at 11.80, to create the largest block of open interest in the name. CMS traded near 9.20 in late Dec, and recently increased their dividend. Earnings due in late Feb and this buyer may be taking steps to protect his holdings given the recent rise in shares.

Aggressive put buying is taking place in thinly traded health product maker Chattem today. Shares near $67.44 and an opening customer buyer has been lifting March 60 Puts, paying from 1.85 to 2.15 in small lots totaling 620 contracts. Shares sank nearly 10% early yesterday on earnings, before a bounce and close at 66.63. Today’s flow suggests concern for further volatility and downside potential in the short term.

Updated. Apollo (P/C Chart, news, chart, volatility) May 95/115 call spread is seeing some action Friday. Shares are down 60 cents to $82.23 and the top trades of the day hit early when 3,000 May 95 calls traded near the offering price for $5.56 while 3,000 May 115 calls traded on the bid for $1.40. According to an exchnage-floor contact, the spread traded was tied to 72,000 shares, or on 24 delta. In any event, the activity seems to reflect a bullish veiw on the education company. The strategist paid $4.16 (excluding commissions) and has a potential payoff of $15.84 if APOL rallies to $115 or more by the May options expiration. The spread was repeated more than once and volume in both contracts exceeds 5,000.

Intuitive Surgical (P/C Chart, news, volatility) is up $1.46 to $103.47 and calls are active amid takeover chatter. J&J (JNJ) is looking at ISRG according to speculation making the rounds Friday. In the options market, 9,700 ISRG calls and 3,900 puts traded. Feb 120 and March 125 calls are the most actives, with all of today’s 2,600 contracts traded in small size–fewer than 90 contracts at a time.

Harmony Gold (P/C Chart, news, chart, volatility) May 12.5 calls are active. More than 11,200 traded, including two blocks of 7,260 and 1,000 contracts at the offer for $1.55 and $1.50. HMY is up 21 cents to $12.06 after gold rose $23 to $929.50 an ounce.

Call options on James River Coal (P/C Chart, news, chart, volatility) are heating up. 3,075 traded, or about 6X (598%) the expected for midday trading. Most of the action is in the Feb 17.5 and March 20 calls, with about 2,900 traded in lots of 550 or fewer contracts. Looks like buyers dominating the order flow, paying 45 cents for 17.5s and 15 and 20 cents for the 20s. The action comes a few days after a regulatory filing showed Steelhead partners buying 65,000 JRCC shars for $890,136. The stock is down 42 cents to $14.19.

Dollar Tree (P/C Chart, news, chart, volatility) March puts at the 42.5, 40, and 37.5 strikes all saw open interest increase by roughly 3000 contracts. The top trades of the day Thursday included: 2000 Mar 42.5s ask-side for $2.78, 2000 Mar 40 puts mid-market for $1.75, and 2000 March 37.5 puts for $1.10. Since the open interest data suggests new positions in all three, the activity looks like a substantial “tree”, or buying the 42.5s and selling the other two. So it looks like an investor opened a put Tree on Dollar Tree. Isn’t it ironic?

As noted yesterday, Seagate (P/C Chart, news, chart, volatility) has been the subject increasing call activity in recent days. Open interest in STX calls is up 11.4 percent to 105K contracts since the stock set record lows on Jan 23, two days after posting disappointing earnings. Insiders have been buying as well. An SEC filing out last night showed the company’s CEO Luczo buying 500K shares at an average of $3.56 on 1/27. STX is down 20 cents to $3.84 today.