Conventional wisdom says that insiders and 10% owners really only buy shares of a company for one reason — they believe the stock price will rise and they want to profit from. So insider buying can be an encouraging signal for potential investors, particularly during periods of uncertainty.

Insiders continued to add shares despite overall market volatility and economic uncertainty. The following are some of the most noteworthy insider purchases reported in the past week.

A director at Axis Capital Holdings Limited AXS 2.78% indirectly bought less than 1.35 million shares of this Bermuda-based company at between $38.77 and $42.50 each. That totaled around $55.67 million, and it almost doubled the director's stake.

A Fate Therapeutics Inc FATE 4.46% director indirectly picked up more than 1.41 million shares of this biopharmaceutical company for $28.31 each.

That totaled about $40 million and brought the stake to nearly 12.63 million shares.

Several insiders at Cannae Holdings Inc CNNE 2.66%, including President Brent Bickett, took advantage of a secondary offering of $37.50 per share. The more than 248,300 shares of this investment firm scooped up by these insiders totaled more than $9.31 million altogether.

An AES Corp AES 0.67% director returned and indirectly purchased another 500,000 shares of the Virginia-based electric utility at prices ranging from $12.19 to $12.25 each. That totaled about $6.11 million. The same director bought 500,000 shares in May.

Fox Corp FOX 2.93% CEO Lachlan Murdoch bought more than 101,500 shares last week. At $28.29 per share, that added up to more than $2.87 million. Note that pursuant to a transfer plan, those shares were simultaneously sold to a family trust at the same price.

A director at Cigna Corp CI 0.81% picked up fewer than 5,500 shares of this Connecticut-based insurer. At an average price of about $187.36 per share, that came to more than $1.02 million. Note that some executives were selling shares earlier in the month.

CEO Thomas Greco paid $136.13 each for more than 7,200 Advance Auto Parts, Inc. AAP 1.98% shares. That cost him about $991,707 and brought his stake to almost 132,500. A couple of other executives sold a small number of shares earlier this month.

A director added more than 9,100 Bristol-Myers Squibb Co BMY 0.65% shares to his stake. At a share price of $54.50, that totaled shy of $500,000, and it increased his stake by about 41%. Note that a pair of executives sold over 28,000 shares back in May.

An Uber Technologies Inc UBER 3.28% director indirectly acquired some shares of this San Francisco-based ride-hailing company early last week. At prices ranging from $31.57 to $31.66, the more than 15,400 shares added up to about $497,400.

A smaller amount of insider buying occurred at Cooper Companies Inc COO 0.85%, Enterprise Products Partners L.P. EPD 0.57%, Park Hotels & Resorts Inc PK 2.82%, Trust Financial Corp TFC 2.79% and VF Corp VFC 0.36%.