Ticket KPIs · Ticket resale glossary
Stock Delta
Also known as: Restock size, Stock change, Tickets restocked
Stock delta is the change in an event's available tickets between two checks: positive when tickets were added (a restock), negative when they were removed or sold.
Small deltas — a ticket or two coming back from an unpaid basket — happen constantly. Large positive deltas are the ones that matter: released holds, a new drop or extra capacity.
Filtering alerts by a minimum stock delta keeps a ticket monitor quiet until a restock is big enough to act on.
How stock delta is calculated
Stock delta compares two consecutive checks of the same inventory. Formula: stock delta = available tickets now − available tickets at the previous check. 120 tickets available at 10:00 and 160 at 10:01 is a delta of +40; 160 followed by 150 is −10.
It can be measured for the whole event or for one section, price level or ticket type. A section-level delta is often more useful: +40 on the floor matters, while +40 spread across the back of the upper tier may not (see section availability).
Positive vs negative stock deltas
A positive delta means tickets were added: released holds, expired baskets, cancelled orders or a fresh ticket drop. That's the change buyers want to be alerted to. A negative delta means tickets left the pool because they sold, went into someone's basket or were withdrawn. A run of negative deltas straight after a restock shows how quickly it was absorbed.
Worked example: setting a minimum restock size
A monitor watches a sold-out arena show. Over one evening it records deltas of +1, +2, +1, +38, +1, +3 and +2. Without a filter that's seven alerts, six of them a ticket or two from expired baskets that are gone again within seconds. With a minimum restock size of 10, only the +38 sends a notification to the Discord channel.
The +38 is the one worth acting on. A block coming back in one go is usually a released hold or a batch of cancelled orders, and it gives several buyers a real chance at once. The filter removes six alerts of noise and keeps the one that matters.
Choosing a stock delta threshold
There's no universal right number; it depends on what you're trying to catch:
- Buying for yourself: a low threshold of 1 or 2 is fine, since any ticket might be the one you need.
- Reselling pairs: set the minimum at 2 or more and combine it with a quantity filter so the seats come together.
- High-volume events: on stadium shows with constant churn, thresholds of 10 to 20 keep a channel readable.
- Narrow filters: use a low threshold on a tight section filter and a higher one when watching the whole event.
Pitfalls with stock deltas
A delta depends on how often the inventory is checked. Two restocks of 20 between checks show up as one +40, and a restock of 30 that loses 25 tickets before the next check appears as +5 — faster checking gives truer deltas. Resale can also produce deltas that aren't restocks at all: a broker listing a block of 50 is +50 on resale stock. Read the delta together with the ticket type before acting on it in a ticket monitor.
Catch it with Eventory
Eventory notifications show how many tickets were restocked or removed, and monitors can ignore changes below a minimum restock size.
Frequently asked questions
What does stock delta mean?
It's the change in available tickets between two checks of an event. A positive number means tickets were added, which is a restock; a negative number means tickets were sold, reserved or removed.
What is restock size?
Restock size is another name for a positive stock delta: how many tickets came back on sale in one change. Alerts often use a minimum restock size so that one or two tickets from an expired basket don't trigger a notification.
Why do I get alerts for just one ticket?
Because single tickets return to sale all the time from expired baskets and failed payments. If you only care about larger releases, set a minimum restock size on your monitor so small changes are ignored.
How do I filter ticket alerts by restock size?
Eventory monitors let you set a minimum restock size alongside section, price, quantity and ticket-type filters, and each notification shows how many tickets were restocked or removed.