A high velocity event, abbreviated HVE, is Amazon's term for a short, pre-scheduled sales period in which traffic, orders and advertising demand run far above normal levels. Prime Day, Prime Big Deal Days, Black Friday and Cyber Monday are the standard examples. The label exists because the retailer, its third-party sellers and its advertising auction all behave differently when a quarter's worth of intent is compressed into a few days: discount minimums rise, submission deadlines harden, fees change and server capacity is provisioned in advance. Calling a period an HVE is shorthand for saying that ordinary operating rules no longer apply.

The term began as internal vocabulary and has surfaced publicly only in fragments. No formal definition has been published, and the documents that use it disagree on which events qualify.

What counts as a high velocity event

Three dated sources list different members. On August 31, 2026, Amazon told sellers that a new business-only deal type would require a 15% minimum discount for High Velocity Event deals, and defined the category by example as Prime Big Deal Days, Black Friday and Cyber Monday. The Federal Trade Commission (FTC) complaint filed against Amazon the same day cites a longer internal list: Prime Day, Prime Big Deal Days, Black Friday, Cyber Monday and the pre-Christmas period. A January 2026 Amazon job listing for an HVE lead at Zappos, its footwear subsidiary, named Prime Day and Prime Big Deal Days alongside seasonal promotions such as the Labor Day Sale and the Big Spring Sale, according to the posting.

Velocity refers to rate rather than volume: orders, page loads and bids per second. A Hacker News commenter describing time at Amazon wrote in November 2022 that alarms built on five-minute-delayed metrics were adequate on normal days but too slow during Black Friday or Prime Day, when spikes outran any human response. During Prime Day 2019, Amazon DynamoDB, the database behind the retail sites and fulfilment centres, peaked at 45.4 million requests per second, according to Amazon Web Services (AWS). By Prime Day 2025 the peak was 151 million.

How the label changes the rules

For sellers, an HVE is first a calendar of commitments. For the 2026 holiday season, Amazon priced Best Deals, Lightning Deals and Prime Exclusive Discounts at 100 dollars upfront per promotion plus 1.5% of promotional sales, the variable part capped at 5,000 dollars. Early submission removed 50 dollars from the fixed fee. Prime Big Deal Days submissions closed on September 8; the Black Friday Week and Cyber Monday window closes on October 20. Stock deadlines ran in parallel: September 2 for Amazon Warehousing and Distribution (AWD), September 9 for Fulfillment by Amazon (FBA) shipments with minimal splits, and September 16 for the Amazon-optimized splits most sellers choose. A peak fulfilment surcharge averaging 0.32 dollars per unit applies from October 15, 2026 to January 14, 2027.

Discount floors shift too. Under the business-only deal type, a product with a Business Price of 200 dollars can be listed at no more than 180 dollars in a regular deal, reflecting the 10% minimum, but at no more than 170 dollars during an HVE. Deals run from one hour to 30 days and require a rating of at least 3.5 stars.

On the advertising side, an HVE is a demand shock against fixed inventory: search result pages do not grow during Prime Day, but bidders multiply. CommerceIQ, a commerce analytics vendor, measured cost per click (CPC) during the June 23 to 26, 2026 Prime Day at 37.3% above the 14-day pre-event baseline, with beauty up 97%. Return on ad spend (ROAS) fell 18.8% against that baseline because click prices rose faster than attributed sales. The figures are the vendor's own.

Buyers organise campaigns in three phases: a lead-in, typically one to two weeks, the event itself, and a lead-out for retargeting. Amazon Marketing Cloud (AMC), the company's clean room for pseudonymised advertising and shopping signals, offers an instructional query named Tentpole Phase Overlap that compares performance across the three windows, according to agency Tinuiti.

The auctioneer's side of the event is where the term reached a courtroom. According to the FTC complaint, Amazon raised the ceilings on a reserve price applied after its auctions had ranked bidders around HVEs, reasoning in internal documents that seasonal demand would mask the increase.

Origin and evolution

The events predate the label's public use by a decade. Amazon ran the first Prime Day on July 15, 2015 to mark its 20th anniversary; traffic ran 19% above Cyber Monday 2014 and 23% above Black Friday 2014, according to McKinsey. The event lasted 36 hours in 2018 and 48 hours in 2019. The pandemic moved the 2020 edition to October 13 and 14, the first to fall in the fourth quarter, according to CNBC. The 2021 edition ran in June.

October became permanent in 2022 with the Prime Early Access Sale on October 11 and 12, renamed Prime Big Deal Days in 2023. Black Friday lengthened as well: Amazon's 2023 event opened on November 17 and ran 11 days to Cyber Monday. A Big Spring Sale open to non-members followed in 2024. Prime Day became a four-day event from July 8 to 11, 2025, then moved to June for 2026, only the second June edition.

Each addition widened the set of periods needing HVE treatment. A calendar that once had one summer peak and one winter peak now carries at least five named events.

Why it matters for marketers

Advertising revenue follows the calendar. Amazon reported advertising services revenue of 19.8 billion dollars for the second quarter of 2026, up 26%, in a quarter that contained Prime Day while its 2025 comparison did not. Analysts had flagged the quarterly reshuffle in February. A growth rate that straddles a relocated event describes scheduling as much as demand.

Concentration also creates timing risk. Amazon announced the 2026 Prime Big Deal Days dates on September 14, two days before the main FBA inventory deadline, so stock and deals had to be committed before the event was dated. In 2025 the October dates were confirmed on September 16.

The economics are shifting too. During Prime Day 2026, CommerceIQ recorded ad spend down 8.8% year on year and product page traffic down 10.3%, while unit conversion rose 17.1% to 20.0%. Amazon's announcement for the October event promoted AI price alerts and automatic purchasing, features that could move conversions away from the pages on which brands bid.

Limitations and disputes

The absence of a public definition is the first weakness. Because the Business Deals notice defines the category only by example, it does not settle whether a Big Spring Sale deal falls under the 10% or the 15% floor.

The second concerns pricing. The FTC and 22 state attorneys general allege that Amazon relaxed constraints on its soft reserve around HVEs because seasonality acted as a confounder, hiding the change from advertisers who might otherwise have turned to bid shading. According to the complaint, the auction team won approval on July 11, 2023 to raise the surcharge constraint across the United States marketplace for day two of Prime Day, and one grocery advertiser reported CPCs up more than 90%. The share of Sponsored Products clicks charged at the advertiser's full bid reached 79.1% in 2024, the complaint states. Amazon rejects the case, arguing that its reserves reflect the market value of placements, that no advertiser pays more than its bid, and that inflation-adjusted average CPC for Sponsored Products search ads was flat from 2019 to 2024. The allegations are unproven. Case 2:26-cv-03097 is pending in the Western District of Washington, and followed FTC inquiries opened in September 2025.

The third concerns the discounts themselves. A proposed class action filed on September 22, 2025 alleged that Prime Day percentage discounts were calculated from list prices at which products had not sold in the preceding 90 days. Amazon tightened List Price validation from April 23, 2026.

Measurement is the fourth. Event results depend on the chosen baseline: CommerceIQ's Prime Day 2026 CPC was down 0.7% year on year yet 37.3% above the preceding fortnight. Platform-level and market-wide datasets covering the same days diverge because they count different populations. Stockouts blur attribution further: CommerceIQ measured out-of-stock losses up 185% during the event, after pre-event losses had already risen 24%.

Not the same as

Tentpole event. A media planning term borrowed from film scheduling, applied by agencies to any retailer's marquee sales. An HVE is Amazon's own operational category, used in seller notices and, according to the FTC, auction planning.

Peak season. A fulfilment fee window, October 15 to January 14 for the 2026 cycle, that includes weeks with no event at all.

Deal type. Lightning Deals, Best Deals and Prime Exclusive Discounts are promotion formats that run during HVEs and outside them. They are instruments, not events.

T12. Agency shorthand for the Thanksgiving to Cyber Monday stretch, which ran from November 20 to December 1, 2025, according to agency Podean. It describes one HVE window rather than the category.

Recent developments

As of September 2026, the category is widening in two directions. Business Deals opened to more than 11 million business organisations in ten marketplaces, with email and push promotion during major events offered at no extra cost until December 31, 2026. On September 14, Amazon set Prime Big Deal Days for October 6 and 7 across 22 countries, up from 19 in 2024, with new deals released three times a day. Black Friday falls on November 27, roughly seven weeks later. The October event will be the first HVE held since the FTC filed its complaint.

Timeline

  • July 15, 2015: Amazon holds the first Prime Day to mark its 20th anniversary
  • July 2016: the second Prime Day runs on added server capacity equal to all of AWS and Amazon.com in 2009
  • July 16, 2018: Prime Day runs for 36 hours
  • Late 2018: Amazon begins applying undisclosed soft reserves to Sponsored Brands auctions over Christmas, according to the FTC complaint
  • July 2019: Prime Day runs for 48 hours; DynamoDB peaks at 45.4 million requests per second
  • October 13 to 14, 2020: the pandemic moves Prime Day into the fourth quarter for the first time
  • June 2021: Prime Day runs in June for the first time
  • December 10, 2021: the Sponsored Products auction team removes a click-level surcharge constraint and prices spike, according to the FTC complaint
  • October 11 to 12, 2022: Amazon adds a second annual members-only event, the Prime Early Access Sale
  • July 11, 2023: Amazon raises the surcharge constraint for day two of Prime Day, according to the FTC complaint
  • August 8, 2023: Amazon names its October event Prime Big Deal Days
  • November 17, 2023: Amazon's Black Friday event opens, running 11 days to Cyber Monday
  • 2024: Amazon adds the Big Spring Sale, open to all customers
  • July 8 to 11, 2025: Prime Day runs for four days for the first time
  • September 12, 2025: the FTC opens consumer protection inquiries into Amazon and Google over search advertising pricing
  • September 22, 2025: a proposed class action alleges inflated reference prices in Prime Day discounts
  • November 20 to December 1, 2025: Amazon runs its Thanksgiving to Cyber Monday deal window
  • January 2026: an Amazon job listing seeks an HVE lead for Zappos
  • April 23, 2026: Amazon tightens List Price validation rules
  • June 23 to 26, 2026: Prime Day runs in June
  • August 31, 2026: Amazon names High Velocity Event deals in its Business Deals notice; the FTC and 22 states file Case 2:26-cv-03097
  • September 14, 2026: Amazon sets Prime Big Deal Days for October 6 to 7 across 22 countries
  • September 16, 2026: main FBA inventory deadline for Prime Big Deal Days
  • October 20, 2026: deal submission deadline for Black Friday Week and Cyber Monday
  • November 27, 2026: Black Friday

Summary

Who. Amazon defines and schedules high velocity events. Third-party sellers, vendors and brands commit deals and inventory to them; advertisers and agencies bid through Sponsored Ads and Amazon DSP during them. The FTC and 22 state attorneys general have made Amazon's auction pricing around them the subject of litigation.

What. An internal Amazon category for short, pre-scheduled sales periods with sharply elevated traffic, orders and ad demand, carrying their own discount minimums, deal fees, inventory deadlines, infrastructure preparation and, according to the FTC, auction pricing behaviour. No public definition exists, and published lists of members differ.

When. The events trace to the first Prime Day on July 15, 2015. The label appears in engineering discussion by 2022 and entered a public seller notice on August 31, 2026, the same day the FTC complaint quoted it.

Where. Amazon marketplaces worldwide, with Prime Big Deal Days in 22 countries for 2026; within the business, the label spans seller tooling, fulfilment, cloud infrastructure and the Sponsored Ads auction.

Why. Compressing demand into a few days changes costs and behaviour across the retailer at once. The label lets Amazon apply event-specific rules, and it has become the reference point for disputes about how Amazon prices advertising when demand peaks.