Twitter shares, options activity jump on potential sale news

** Twitter Inc's options on pace for their busiest day ever, on reports the social media co getting closer to a sale. TWTR rises as much as 23 pct

** Twitter has initiated talks with several tech companies to explore selling itself, a person familiar with the matter said on Friday

** Earlier this morning, CNBC, citing unnamed sources, said that Twitter's possible suitors include Alphabet's Google and Salesforce.com

** 817k TWTR contracts traded by 1:00 pm ET (1700 GMT) on Friday; second-highest one-day trading volume since Dec. 26 2013, when volume hit 904k contracts as TWTR shares hit a record high of $74.73

** TWTR Oct 20 calls the most active with 33k contracts traded; overall calls outnumber puts 2.4x, per Thomson Reuters data

** Options trading sentiment leans bullish, per Trade Alert data

** TWTR 30-day ATM implied vol jumps to a two-month high of 67 pct from 49 pct on Thursday, per Trade Alert data

** Twitter's short interest amounted to 7.2 pct of shares outstanding as of Aug 31, lowest since March 15 (TR data)

** The stock often jumps on rumors that a bid is afoot, none of which have so far developed into a deal

** TWTR shares last up 19 pct to $22.13; earlier it touched $22.89, highest price since Jan 5

** Stock had been down premarket on downgrade to "underperform" by RBC