The S&P 500 Index (SNPINDEX:^GSPC) fell 7.7 points, or 0.34%, on Aug. 31. Today's modest sell-off wasn't enough to wipe out what has been a great month for investors; the index finished August up 7%, making for the best month since April. 

Today's decline was led by sell-offs in some of the worst-performing industries so far this year, with oil refiner Hollyfrontier (NYSE:HFC) stock falling 7.5%, shares of casino operator MGM Resorts International (NYSE:MGM) down 5.7%, and shares of airline and cruise line American Airlines (NASDAQ: AAL) and Carnival Corp. down 4% on the day. 

Empty hotel lobby.

Empty resorts and hotels could be a thing for some time to come. Image source: Getty Images.

Tech giant Apple (NASDAQ:AAPL) was by far the best-performing of the megacap stocks. Of the 15 S&P 500 stocks with at least $300 billion market cap, only three gained in value, and only Apple shares were up more than 2% on the day.

In other notable news, Berkshire Hathaway (NYSE:BRK.B) CEO and superinvestor Warren Buffett turned 90 over the weekend, and the company disclosed $6 billion-plus investments in five Japanese companies over the past year. 

Apple up after stock split

Today was a notable day for Apple investors, since the company's stock officially traded post- the 4-for-1 stock split. The fact that a stock split doesn't actually create any value for shareholders -- it's like cutting a pizza into more and smaller pieces -- didn't stop investors from buying, with shares up 3.4% on the day. 

In fairness, it wasn't just the split helping drive Apple's price up. Multiple Wall Street analysts released investor notes today, including their split-adjusted price targets for the newly divided shares, and touting the potential of an upcoming "supercycle" as consumers upgrade to the company's new 5G-enabled phones, set to be released in coming months. Other analysts? Not so much. 

Berkshire bagging Asian elephants

Japan is a collection of small islands, with a massive population that it doesn't have all of the resources it needs to support. Warren Buffett, ever the contrarian, has made a sizable bet on Japan's biggest conglomerates.

In a weekend press release, Berkshire disclosed that it had acquired 5% of the five biggest of Japan's publicly held trading companies, worth an estimated $6.5 billion. Moreover, Berkshire made it clear that these aren't viewed as short-term value opportunities but are expected to be long-term holdings that very well could grow. Berkshire could invest what works out to be about double the stake in the five it has already acquired, up to a 9.9% stake of each. 

Whether Buffett's big bet on Japan, with its own economic struggles and an aging demographic pay off for shareholders remains to be seen. Despite a half-century of market-crushing returns, Berkshire has substantially trailed the market over the past decade: 

BRK.B Chart

BRK.B data by YCharts

Bad day for energy, travel, hospitality stocks

Refining stocks in particular took it on the nose today, with Phillips 66 (NYSE:PSX), Marathon Petroleum (NYSE:MPC), and Valero Energy (NYSE:VLO) joining Hollyfrontier down more than 4% today and making four of the 10-worst S&P 500 stocks today refiners. The impact of the coronavirus pandemic on fuel demand continues to weigh on most refiners; while they can generally navigate the ups-and-downs of oil prices just fine, the double-digit decline in fuel demand continues to weigh on the sector. 

For hospitality and travel stocks, the implications of the pandemic to continue weighing on these businesses for some time to come seems to be catching up to their stocks. The past month has been relatively good for share prices, but the struggles of their operations hasn't improved in any meaningful way. MGM's big sell-off came after last week's run-up, even following an announcement that it would be laying off 18,000 employees. Joining MGM on the sell-off was Wynn Resorts, with its stock down almost 5%. 

Airline stocks fell sharply with Alaska Air (NYSE: ALK) and American falling on United Airlines (NASDAQ:UAL) announcement that it was dropping change feesDelta Airlines and American both announced by the end of the day that they would follow suit. 

Why a sell-off on a customer-positive announcement? A combination of the reality -- airlines are in trouble, and tens of thousands of airline jobs are a near-certainty to get cut in the weeks ahead, with travel still down 70% or more -- and the acknowledgement by investors that this is a move that's likely out of desperation. United is likely hoping the move will encourage at least some customers to book future travel now, giving the company the extra cash it so desperately needs to keep in business. 

Investors don't seem so keep on the move as helping out very much. 

Looking ahead: Will Congress act?

Summer recess for our elected representatives is coming to an end, and Congress will reconvene after legislators have spent time in their home states, meeting with their constituents. More than a month has passed since the $600-per-week federal increase in unemployment benefit expired, and with unemployment still at record levels, a lot of attention will be paid to what happens in the halls of Capitol Hill in the days to come. 

As a result, the market's relative calm over the past few weeks could come to an end. With a presidential election coming, and the campaigning likely to be contentious at best, it's hard to call the outcome of the return to negotiations for additional economic support to the millions of Americans facing financial struggles as the coronavirus pandemic continues to weigh on the economy. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.