Thoughtworks Holding, Inc. (NASDAQ:TWKS – Get Rating) was the recipient of a significant increase in short interest in December. As of December 15th, there was short interest totalling 1,380,000 shares, an increase of 47.8% from the November 30th total of 933,800 shares. Currently, 1.6% of the shares of the stock are sold short. Based on an average daily volume of 858,000 shares, the short-interest ratio is presently 1.6 days.

OP Bancorp (NASDAQ:OPBK – Get Rating) saw a large increase in short interest in the month of December. As of December 15th, there was short interest totalling 39,900 shares, an increase of 86.4% from the November 30th total of 21,400 shares. Approximately 0.4% of the shares of the company are short sold. Based on an average daily volume of 27,400 shares, the days-to-cover ratio is presently 1.5 days.

Citigroup (NYSE:C – Get Rating) had its price objective decreased by investment analysts at Oppenheimer from $90.00 to $87.00 in a note issued to investors on Wednesday, Benzinga reports. The brokerage presently has an “outperform” rating on the stock. Oppenheimer’s price objective indicates a potential upside of 95.99% from the company’s current price.

Amazon.com, Inc. (NASDAQ:AMZN) was the target of some unusual options trading activity on Wednesday. Investors purchased 1,794,328 put options on the stock. This is an increase of approximately 74% compared to the average volume of 1,029,433 put options.

Topaz Energy Corp. (TSE:TPZ – Get Rating) Director Mike Rose acquired 10,000 shares of the company’s stock in a transaction that occurred on Wednesday, December 28th. The shares were acquired at an average price of C$21.00 per share, with a total value of C$209,984.00. Following the acquisition, the director now owns 443,470 shares in the company, valued at C$9,312,160.45.

Neuronetics, Inc. (NASDAQ:STIM – Get Rating) was the recipient of a significant increase in short interest in December. As of December 15th, there was short interest totalling 436,700 shares, an increase of 120.3% from the November 30th total of 198,200 shares. Currently, 1.8% of the company’s stock are short sold. Based on an average trading volume of 197,700 shares, the days-to-cover ratio is presently 2.2 days.

Stitch Fix, Inc. (NASDAQ:SFIX – Get Rating) saw some unusual options trading activity on Tuesday. Stock investors purchased 9,598 call options on the stock. This is an increase of 49% compared to the typical daily volume of 6,424 call options.

DexCom, Inc. (NASDAQ:DXCM – Get Rating) Director Steven Robert Pacelli sold 412 shares of DexCom stock in a transaction dated Friday, December 23rd. The shares were sold at an average price of $112.57, for a total transaction of $46,378.84. Following the completion of the transaction, the director now directly owns 137,288 shares of the company’s stock, valued at approximately $15,454,510.16. The sale was disclosed in a document filed with the SEC, which is available through the SEC website.

Kinder Morgan, Inc. (NYSE:KMI – Get Rating) VP John W. Schlosser sold 1,500 shares of the company’s stock in a transaction dated Tuesday, December 27th. The shares were sold at an average price of $18.18, for a total transaction of $27,270.00. Following the sale, the vice president now owns 21,219 shares of the company’s stock, valued at $385,761.42. The transaction was disclosed in a filing with the Securities & Exchange Commission, which can be accessed through the SEC website.

Central Puerto S.A. (NYSE:CEPU – Get Rating) announced a quarterly dividend on Tuesday, December 27th, Wall Street Journal reports. Investors of record on Tuesday, January 3rd will be given a dividend of 0.1649 per share on Monday, January 9th. This represents a $0.66 annualized dividend and a dividend yield of 10.77%. The ex-dividend date of this dividend is Friday, December 30th.