Micron is up about 38% for the week as the memory chip assembly continues to be the same

Micron technology stocks are on fire this week amid a global shortage of memory chips, with momentum driving the stock amid growing enthusiasm for the entire semiconductor sector.

Shares rose more than 15% to close at $746.81 on Friday. The stock has gained about 38% in the week, and is up about 84% in the past month.

Micron marked its best week since December 2008, when it traded below $5 a share after the Great Recession. The company’s market cap is currently over $840 billion, according to LSEG.

Micron is not alone among chip makers. Shares of AMD rose 26% for the week, touching a new 52-week high on Friday and bringing the company’s market cap to more than $740 billion.

Intel jumped 25% in the week and more than doubled in the past month on the much-discussed comeback of the CPU maker.

Demand for memory chips is emerging as a sign of the current phase of AI buildout, driven by total capex from hyperscalers that could exceed $1 billion by the end of next year, according to Bank of America and Evercore.

While graphics processing units (GPUs) have been the focus of AI hardware buildout so far, memory, storage and CPUs have been stealing the spotlight.

Amid the shortage of memory chips, prices and margins for memory makers have been expanding, while hyperscalers have complained about rising costs of goods and services used by end users.

DRAM and NAND are the two most popular types of memory. DRAM is faster and more chaotic while Flash-based NAND is slower and more reliable. Both are important for AI performance.

Micron, Samsung and SK Hynix together produce more than 90% of the world’s DRAM, according to several equity research reports.

Like Micron, South Korean memory chip makers are in trouble. Samsung joined the trillion-dollar valuation club this week along with companies like it an apple, Alphabets again Microsoft.

SK Hynix is ​​fielding a number of offers from global technology companies looking to invest in new, dedicated memory production lines to boost productivity, Reuters reported on Friday.

Another issue was an equipment financing agreement from the company’s customers related to ultraviolet lithography equipment, the media reported.

“MU remains in good shape across the memory space with advanced DRAM nodes helping cost declines year over year, while NAND is seeing increased layer counts drive better costs and increase wafer capacity,” Mizuho analyst Vijay Rakesh wrote in a research report this week.

Micron has been taking a large share of retail trading in general over the past few months, researchers said. Net purchases rose to their highest level in two years in mid-April, according to Vanda Research.

That comes as buying of the stock by retail investors in recent months has softened compared to the past few years, said Viraj Patel, strategist with Vanda in an interview with CNBC on Friday. “So, arguably, Micron commands a much larger share of the flow and attention,” he added.