Photo by JESHOOTS.COM on Unsplash.

Insider buying can be an encouraging signal for potential investors, especially when markets face uncertainty or are near all-time highs. A couple of chief executive officers and an executive board chair were among the insiders buying shares this past week. As well, a master limited partnership, a real estate investment trust, and a conglomerate were among companies that participated in notable insider buying.

Note that, though earnings reporting season is waning, some insiders are still prohibited from buying or selling shares. Here are some of the most noteworthy insider purchases that were reported in the past week.

Chief Executive Officer Robert Duggan of Summit Therapeutics Inc (SMMT) bought more than 11.36 million shares, and another executive picked up almost 389,100 shares via trust, all at an offering price of $5.24 apiece. These purchases totaled over $61.59 million altogether and lifted Duggan's stake to more than 67.66 million shares.

The purchase of about 667,980 more PennyMac Financial Services Inc (PFSI) shares last week by a director (and frequent buyer) for $56.84 to $58.86 per share totaled $38.66 million. It also raised that director's stake to more than 2.17 million shares. Note that the stock ended the week trading at around $60.25 a share.

Wireless communication company Radius Global Infrastructure Inc saw a pair of beneficial owners indirectly buy 925,000 shares each in the wake of better than expected first-quarter sales numbers. At $13.95 per share, these insider purchases added up to more than $25.8 million altogether.

The Avis Budget Group Inc. (CAR) executive board chair, Bernardo Hees, indirectly scooped up 63,000 shares midweek. At prices ranging from $74.94 to $79.94 a share, the purchases totaled around $5 million. The timing looks fortunate, as the stock ended last week trading at around $86.83 a share.

Biglari Holdings Inc (BH) CEO Sardar Biglari indirectly added more shares to his stake in this San Antonio-based conglomerate in the past week. The more than 19,300 Class B shares had prices of $147.80 to $159.00 apiece, costing him around $2.90 million. Those shares ended the week trading at $156.03.

Specialty chemical products provider Univar Solutions Inc (UNVR) saw two of its directors pay $25.46 to $26.00 apiece in the middle of the week for a combined 105,000 of its shares. That added up to more than $2.7 million. Note that another director sold almost 25,000 shares of this as well.

An American Homes 4 Rent (AMH) beneficial owner indirectly bought 20,000 shares at between $36.84 and $37 apiece. That cost that owner more than $1.99 million and raised the stake to about 17.01 million shares. The real estate investment trust was last seen trading at $37.31 per share.

As it reportedly mulls chemicals business acquisitions, Energy Transfer LP (ET) had a director pick up 200,000 shares indirectly at prices that ranged from $9.48 to $9.56. These purchases added up to more than $1.90 million. The timing seems fortunate here too, as the master limited partnership ended the week at $10.11 per share.

A director added 17,000 more shares of Activision Blizzard, Inc. (ATVI) to his stake last week, about a week after it released a strong quarterly report. The shares were acquired via trust at prices ranging from $93.36 to $95.74 a share, which totaled more than $1.62 million. This same director bought 5,000 shares in the previous week, as well.

Note that a smaller amount of insider buying at CenterPoint Energy Inc (CNP), Corning Incorporated (GLW), Gogo Inc (GOGO), Masonite International Corp (DOOR), and SmileDirectClub Inc (SDC) was reported in the past week, as well.