Semiconductor stocks, led by Micron, are among the month's best performers, while Coinbase shares have benefited from the craze over stablecoins

From the end of May, the S&P 500 was up 1.5% in early trading on Friday. But many stocks of semiconductor manufacturers and providers of related computer hardware had soared by double digits.

Buy-side investors are "super bullish" on memory-chip and hard-disk-drive stocks such as Micron Technology Inc. $(MU)$, Mizuho Securities desk-based analyst Jordan Klein wrote in a recent note to clients.

The memory-chip maker is a leader in dynamic random-access memory chips, which are seeing pricing updates that "all sound super positive," Klein said. Alongside that, Nvidia Corp.'s $(NVDA)$ Blackwell graphics processing units are spurring demand for high-bandwidth memory chips $(HBM)$ - a specialized type of DRAM.

With Nvidia's Blackwell Ultra chips expected to roll out later this year or early next year, "HBM density rises materially," Klein said, which would be good for Micron, Samsung Electronics Co. (KR:005930) and other HBM suppliers.

Money managers are "buying into the late June [Micron] earnings given fear they will miss a breakout back to the highs," Klein said, as DRAM pricing improves and demand continues for HBM.

Meanwhile, investors were optimistic after Advanced Micro Devices Inc. $(AMD)$ unveiled its upcoming AI chips and systems last week. In addition to introducing the Instinct MI350 series of AI accelerators at its annual Advancing AI event, AMD announced its Helios AI rack architecture that will be made up of its next-generation graphics processing units - a move that "will be vital to compete with Nvidia," Dave Altavilla, principal analyst at HotTech Vision and Analysis, told MarketWatch in emailed comments.

"Couple this solid road-map view of complete rack-scale solutions with additional rumblings of a couple of big wins at major hyperscalers, and you begin to see the momentum picking [up] for AMD beyond just being an alternative to a supply-constrained competitor," Altavilla said.

Here's a summary of how the 11 sectors of the S&P 500 SPX have performed so far this month, through about 9:45 a.m. Eastern time on Friday:

It is no surprise to see the energy sector topping the list for gains this month, in light of the conflict between Israel and Iran. And the possibility that Iran may try to disrupt shipping through the Strait of Hormuz helped push front-month contract prices for West Texas Intermediate crude oil (CL.1) up 23% from the end of May to $74.61 a barrel early Friday, although oil was actually down slightly for the day.

The information technology sector has been the second-best performer this month, with a 4.5% gain. And if we look at the top 20 performers among the S&P 500 this month, nine of them are in the tech sector, while four are in the energy sector. And Coinbase Global Inc. (COIN), which was added to the S&P 500 on May 19, has soared 22 in June. The cryptocurrency exchange announced a new stablecoin payments service this week.

Here are the 20 best performers for June among the S&P 500, as of early Friday: