With the dog days of summer behind us, temperatures are starting to dip as we approach sweater weather. But something that has refused to cool down is the stock-buying activity of Rep. Marjorie Taylor Greene, Republican from Georgia.

Complementing a variety of stock buys from earlier in September, Greene continued to build out her portfolio, reporting in a recent regulatory filing that she bought Alphabet (GOOG -1.55%), (GOOGL -1.45%), Berkshire Hathaway (BRK.A -0.39%), (BRK.B -0.56%), Intel (INTC -0.69%), Microsoft (MSFT -1.73%), Southern Copper (SCCO -1.47%), and United Parcel Service (UPS -0.20%). The exact amount that Greene invested in each of the stocks was not disclosed; however, her regulatory filing acknowledges that each transaction was valued between $1,001 and $15,000.

Wheels keep on turning with AI investments

Like so many investors, Greene exhibited considerable enthusiasm for artificial intelligence (AI) stocks over the past few months. Alphabet, for example, consistently appears on Greene's buy list. The most recent purchase of Alphabet stock on Sept. 20 is the third such purchase since she first picked up shares of Google's parent company on Aug. 21.

Similarly, Greene recently added to her Intel position (one that she initiated in August) with a Sept. 20 purchase of the semiconductor stock. So far, the investment has proven to be profitable as Intel stock rose nearly 10% since her most recent purchase. Rounding out Greene's AI investments is Microsoft. After picking up shares in April, Greene bought Microsoft stock again in late September. In addition to AI exposure, the Microsoft investment will provide an increase in passive income as the company announced a 10% increase to its dividend on Sept. 16.

More familiar names find their way into the portfolio

It wasn't only AI-related positions that Greene decided to add to on Sept. 20. For one, the Peach State representative chose to pick up more shares of Berkshire Hathaway, a stock that she had previously bought in April. A stellar long-term investment, Berkshire Hathaway helps Greene to offset some of the volatility that she may experience with the tech stocks that she purchased. Over the past 30 years, for example, the S&P 500 rose 789%, while Berkshire Hathaway soared about 1,870%.

UPS is another stock in which Greene has steadily grown a position. Greene first bought UPS stock in July 2024 and twice in September 2024. In addition to gaining increasing exposure to a leading supply chain stock, Greene is generating a more robust passive income stream as UPS stock currently has a 4.9% forward-yielding dividend.

A new face in the crowd

Greene doesn't often buy materials stocks, so the fact that Southern Copper popped up on her list of recent buys was a little surprising. Well, maybe not so surprising. The company is a premier investment opportunity for exposure to -- you guessed it -- copper. And copper is in high demand as the AI boon continues since the metal is critical to the data centers where AI computing occurs. According to metal-producing powerhouse BHP Group, for example, annual global copper demand will rise to 52.5 million tons by 2050, a notable increase over 30.4 million tons in 2021.

With Greene espousing such strong enthusiasm for AI through her other investments, her interest in buying Southern Copper stock is clearly not that unexpected.

Should you follow Greene's lead and make the same buys?

Like monitoring the stock picks of billionaires and industry insiders, keeping eyes on politicians' stock choices is an excellent tactic. Yet experienced investors would advise you that simply copying their stock moves -- or any individual's stock trades for that matter -- is foolhardy and not a recommended investing strategy.

In the case of Greene's recent purchases, though, investors motivated to gain AI exposure would be smart to consider Alphabet, Intel, and Microsoft -- all three of which are industry leaders. And Southern Copper is also a worthwhile consideration for a different approach to the burgeoning AI industry.

Similarly, it's hard to argue against following Greene into a Berkshire Hathaway investment considering Buffett's reputation as one of the most successful investors of all time. With regards to UPS, the threat of a longshoreman strike may pressure the stock and lead to some volatility in the near term. For those with longer time horizons, this may present a good opportunity to scoop up a quality stock at a discount.