The memory cycle
A memory fab takes years to build, so it is planned for a market years away: SK hynix said in September 2022 that it was building M15X "for the next upturn expected to come in 2025". This page runs a small model of that, quarter by quarter, and sets it beside the real thing since 2008.
The pig cycle.
Economists measured this in pigs long before chips. In November 1926 a US Department of Agriculture bulletin by G. C. Haas and Mordecai Ezekiel wrote that "hog prices tend to move in recurring cycles", a fact that "has long been recognized". When the price is high, it said, farmers "are encouraged by the extra profits to increase their output; later the increased supplies reach the market and force the price down". Arthur Hanau published a study of German pig prices in Berlin in 1928 and 1930, as Ezekiel cites it.
In 1938 Ezekiel set out the cobweb theorem, for goods where "a change in price in one period does not affect production until the next period". Supply follows last season's price; demand sets the price for what arrives. Follow the white line, and count the pigs.
Settles: supply reacts less than demand, and each swing is smaller than the last.
Repeats, nearly: each swing is within 8% of the last.
Explodes: supply reacts more than demand, and each swing is bigger than the last.
The two-year pig.
A memory fab takes years. Samsung wrote in July 2017 that its first line at Pyeongtaek was in mass production "With two years of construction since it broke ground in May, 2015". Three recent projects on one clock:
Micron broke ground on its first fab in Idaho in September 2022, when "New DRAM production is targeted to start in 2025"; since December 2025 it has expected first wafer output in "mid-calendar 2027". SK hynix had planned in September 2022 to break ground on M15X that October; it said in April 2024 that it would start at the end of that month, beside its M15 fab, aiming "to complete in November 2025", and in October 2025 it reported "the early opening of a new cleanroom". Micron bought "existing 300mm cleanroom space" in Taiwan, the deal closing in March 2026, and expects meaningful shipments from it "in mid-calendar 2027".
Build your own bust.
Demand grows steadily, with one small surge early on. Each quarter, makers order capacity for the demand they expect when the fab is ready, and order more when the price is high. Change the two things that make the model cyclical: how long a fab takes, and how strongly orders follow the price.
A real maker's spending plan, in its own words: Micron's guidance for fiscal 2026 capital spending went from "approximately $20 billion" on 17 December 2025 to "above $25 billion" on 18 March 2026 and "approximately $27 billion" on 24 June 2026, a figure it states "net of anticipated government incentives"; its fiscal 2025 guidance had been about $14 billion. Of the March step Micron said "the majority of the increase is driven by cleanroom facility-related capex", and "the largest factor is Tongluo, followed by construction spend increase on our U.S. fab projects". Every vintage, on this record.
Eighteen years of swings.
iSuppli said DRAM makers had sold "below their cash costs since the fourth quarter of 2007", and put their operating losses at $7 billion in 2008. Qimonda, fifth in DRAM by revenue in late 2008 by iSuppli's count, filed for insolvency on 23 January 2009, citing "the massive drop in prices in the DRAM industry". Elpida petitioned for corporate reorganization on 27 February 2012; its notice named "the reinforcement of production capacity by investments into plants and equipment implemented proactively in the DRAM industry in 2006 through 2007", after which "the supply significantly exceeded the demand". Micron completed its purchase of Elpida on 31 July 2013.
In 2023 Micron cut wafer starts by close to 30% from their 2022 peak, in DRAM and NAND, and reported a "GAAP net loss of $5.83 billion" for fiscal 2023; SK hynix reported an "operating loss at 7.73 trillion won". In 1Q26 TrendForce's survey found conventional DRAM contract prices up about 93 to 98% on the quarter before.
Twenty makers, then six.
IC Insights, as Evertiq reported it in May 2022, wrote that "boom-bust cycles have lowered the number of major DRAM suppliers from 20 in the mid-1990s to just six today". In the last chapter, Qimonda filed for insolvency and Micron bought Elpida. In 2Q26, by TrendForce's ranking, Samsung, SK hynix and Micron held 87.6% of branded DRAM revenue between them, and CXMT 9.5%.
Mid-1990s: about 20 major DRAM suppliers, by IC Insights' count.
May 2022: 6, by the same count. The three largest held 94% of DRAM sales in 2021.
2Q26: Samsung 39.4%, SK hynix 24.9%, Micron 23.3% and CXMT 9.5% of branded DRAM revenue, by TrendForce's ranking. Building height is share.
Is this time different?
HBM, the stacked memory that sits beside AI processors (Chips on chips), takes more wafers for each bit. Micron said in March 2024 that "HBM3E consumes approximately three times the wafer supply as D5 to produce a given number of bits in the same technology node", and that the ratio rises with HBM4. SK hynix wrote in April 2024 that HBM "requires at least twice as large capabilities to secure the same production as general DRAM products", a statement about capabilities and production rather than a ratio of wafers to bits. Turn wafers over to HBM at Micron's three to one, or at two to one to see a lower ratio.
IDC wrote in December 2025 that "this time is different". Morningstar's analysts wrote in September 2025 that "Foundries and memory makers are exposed to the intense cyclicality of the semiconductor sector", as Business Insider quoted them. TrendForce expects DRAM supply to stay constrained in 2027, and NAND prices to come under pressure in the second half (July 2026). This page takes no side.
From the order to the output.
The model again, from the side. In its second boom, fabs are ordered over 9 quarters while the price climbs from 0.89× to 1.33×, and come on line over the next 9 while it falls to 0.73×: our model, not a market.
Named on this page, and on this record: Samsung Electronics, SK hynix, Micron, CXMT and PSMC, which sold Micron the Tongluo site; Infineon, Qimonda's former parent. Micron's Tongluo site on the fab map.
- What a fab buyswhere the money in a fab goes11
- Chips on chipsHBM and why it takes more wafers09
- What a chip costsfrom wafer price to chip price10