With the Dow Jones industrial average hovering near all-time highs, insider selling has heated up around at public companies around the United States. According to the Wall Street Journal, public executives have sold at least $100 million of stock since the November 2016 election. (See also: Weekly CFO Sells Highlights.)​​

One of the most notable technology stocks to experience a bump in insider selling in recent weeks is cloud-computing giant Salesforce.com (CRM).

On Jan. 28, 24/7 Wall Street reported that Keith Block, the COO and president of the company, sold 150,000 shares of company stock. According to Reuters, Block bought the stock on the same day for $37.95 and sold it at $78.00 share. The Jan. 24 deal appeared to have been the result of Block exercising stock options.

Block’s buying and selling of Salesforce stock came one day before CEO Marc Benioff engaged in a similar deal. On Jan. 25, Benioff bought 10,000 shares of CRM stock for $39.09 per share. On the same day he sold 8,900 shares of CRM stock at $77.84 per share and another 1,100 shares at $78.69 each.

The insider selling comes at a time that Salesforce stock has rallied. From Dec. 28 to Jan. 27, CRM stock gained 13.2 percent. CRM stock closed Friday’s trading session at $78.21 per share. Shares were still off 7.42 percent from their 52-week high. However, shares traded more than 48.6 percent higher than their 52-week low.

As of Jan. 29, Salesforce.com stock was rated a Strong Buy among the 27 analysts covering the stock, according to TipRanks.com. Among those 27 analysts listed, 24 rated the stock a Buy. The average price target for Salesforce was $93.29, a figure that represented potential upside of 19.28 percent.

Some analysts and economists view the spike in insider selling as a sign that the market’s recent rally could soon cool down. Harvard economist Lawrence H. Summers warned investors Sunday, Jan. 29, about the uptick in insider selling.

“While financial stocks have been very strong over the last several months, insider sales have soared,” Summers wrote in the Washington Post about his concerns related to the Dow’s rally since early November. (See also: Insider Selling Isn't Always A Bad Sign.)