There are two investments.
In one case he was not involved with the purchase valued at less than $3000. The broker exercised discretion over the account.
He is not precluded from having his own authority to make investment decisions in a second account.
He participated in a private placement.
The company had a need for funding. As you know private placements typically offer qualified investors an incentive to participate in the offering. Dr. Price had invested in the company previously based on his own due diligence.
If he had purchased the stock on an exchange the money would not go to the company, he would be buying the stock from another investor, or from a broker's inventory of stock.
It was a penny stock, likely thinly traded. The purchase on the open market might tend to be an inefficient purchase for any investor wishing to make a relatively large purchase of a penny stock. He purchased approximately $100,000 in the private placement.
Dr. Price made a rational investment decision and there is nothing inherently nefarious in the transaction. He did not "trade" the stock, he invested in a company he thought had merit.
Dr. Price is an osteopathic surgeon that gave up his practice to serve in congress. His wife is also a doctor. According to public sources their family net worth is nearly $14 million.
Senator Murray is obtuse.