> ## Documentation Index > Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt > Use this file to discover all available pages before exploring further. # Stock-Out Burst (multiple SKUs OOS in <1h), WooCommerce > Stock-Out Burst (multiple SKUs OOS in <1h). Unusual stock-out velocity, viral SKU, fulfilment glitch, or stock-sync plugin failure. Investigate before ad spend wastes. How to read it, why it matters, and how to act on it. **Metrics type:** [Key Metrics](/nerve-centre/overview#metrics-types-explained) • **Category:** [Ecommerce Platform](/nerve-centre/connectors#connectors-by-type) > Unusual stock-out velocity, viral SKU, fulfilment glitch, or stock-sync plugin failure. Investigate before ad spend wastes. ## At a glance > Real-time alert that fires when a burst of WooCommerce SKUs flip to out-of-stock within an hour. Flags viral demand, fulfilment glitches, or stock-sync plugin failures before ad spend wastes. | | | | ------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **What it counts** | `COUNT(products WHERE stock_status changed to 'outofstock' in last 1h)`. Fires when count >5 AND >2σ above the 7D baseline of hourly OOS flips. | | **REST API endpoint** | `GET /wp-json/wc/v3/products?stock_status=outofstock&modified_after=...`. Polled every 10 minutes. | | **VAT / tax / shipping / discounts** | Not applicable, inventory state. | | **Status filter** | Only `stock_status` transition from `instock` (or `onbackorder`) to `outofstock`. | | **Variations** | Variations count separately. A parent product losing 5 size/colour combos in one hour can trip the alert on its own. | | **Currency** | Currency-agnostic. | | **Channels / sources** | Inventory is global across channels. Marketplace plugin pools may not match this card. | | **Self-hosted vs managed-Woo** | Self-hosted with object-cache misconfiguration can produce a false-spike pattern if cache flushes (5 SKUs become "newly OOS" because the cache caught up, not because they actually flipped). Managed-Woo with Redis is steadier. | | **Time window** | `RT` (rolling-1h, polled every 10 min) | | **Alert trigger** | >5 SKUs flipped to OOS in 1h AND >2σ vs 7D baseline; sentiment\_key `out_of_stock_count` | | **Roles** | owner, operations, marketing | ## Calculation Calculated automatically from your WooCommerce data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading. ## Worked example A US homewares brand on managed-Woo, baseline \~1.2 OOS flips per hour. Wednesday 10 Apr 26, 16:00-17:00 UTC. | Hour bucket | OOS flips | Cause | | ----------- | --------- | ----------- | | 14:00-14:59 | 1 | Normal | | 15:00-15:59 | 2 | Normal | | 16:00-16:59 | 18 | Alert fires | Three observations: 1. **Cause was a viral TikTok mention.** A creator featured the brand's "ceramic mushroom mug" line at 15:50 UTC; traffic spiked 8x and 12 specific mug variations sold through their stock within 50 minutes. The remaining 6 OOS flips were tangential bestsellers caught up in the surge. 2. **Self-hosted Woo would have looked similar but for a different reason.** On flaky shared hosting, the same alert can fire when an object-cache flush refreshes stock state for \~50 products at once. The 2σ baseline filter usually prevents this, but persistent alerts after host events warrant a cache audit. 3. **Plugin-induced data shape variance: ATUM Inventory Management.** ATUM stores stock in custom tables and writes to `_stock_status` on a delay (every 5 minutes by default). On ATUM-using stores the alert can lag by up to 5 minutes, which means viral demand may have already wasted ad budget before the alert fires. ## Sibling cards merchants should reference together | Card | Why pair it with this alert | | ------------------------------------------------------------------------------ | ------------------------------------------------------------------ | | [WC Out of Stock](/nerve-centre/kpi-cards/woocommerce/out-of-stock-products) | The cumulative count behind this alert. | | [WC Low Stock](/nerve-centre/kpi-cards/woocommerce/low-stock-products) | The leading indicator, often spikes 1-2 hours before this alert. | | [WC Ads on OOS](/nerve-centre/kpi-cards/woocommerce/ad-spend-on-oos-products) | The action card: pause ad spend on the freshly OOS SKUs. | | [WC Top Products](/nerve-centre/kpi-cards/woocommerce/top-products-by-revenue) | Identifies whether the OOS spike hit revenue-leaders or long-tail. | | [BC Alert OOS Spike](/nerve-centre/kpi-cards/bigcommerce/oos-spike-alert) | Cross-platform peer for agencies. | ## Reconciling against the vendor's own dashboard **Where to look in WooCommerce Admin:** [WP Admin → WooCommerce → Reports → Stock → Out of stock](/wp-admin/admin.php?page=wc-reports\&tab=stock\&report=out_of_stock) shows the cumulative OOS list. WC does not expose hourly flip velocity; this card is the only Vortex IQ view of that. **Why our alert may fire when the merchant sees nothing:** | Reason | Direction | | ------------------------------------------------------------------------------------------------------------- | ------------------------------- | | **Time-zone**. Alert evaluated UTC; WP Admin uses WP-site timezone. Hour buckets may not align. | Both report same events | | **Self-hosted server uptime**. Cache flush after a brief outage can backfill OOS state and look like a spike. | Self-resolves | | **Plugin-version compatibility**. ATUM, Stock Synchronisation plugins update on a delay. | Alert may lag by up to 5-10 min | | **Currency plugin behaviour**. Not relevant for inventory. | n/a | **Cross-connector reconciliation:** | Card | Expected relationship | | -------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------- | | [`google_ads.gads_disapproved_products`](/nerve-centre/google_ads/gads_disapproved_products) | OOS spike on Woo => disapproval spike on Merchant Center within 24-48 hours unless ads are paused. | ***
Same-metric documentation cross-reference * [`bigcommerce.bc_alert_oos_spike`](/nerve-centre/kpi-cards/bigcommerce/oos-spike-alert) * [`shopify.inventory_alerts`](/nerve-centre/kpi-cards/shopify/products-with-zero-negative-stock)
## Known limitations / merchant FAQs **Self-hosted vs managed-Woo, false-alert risk?** Self-hosted with object-cache misconfiguration produces occasional false spikes (cache flush backfills OOS state). Managed-Woo with Redis is steadier. **Status-filter selection, why only `outofstock`?** Backorder-allowed flips are not really stockouts (the customer can still buy). Including them would noise the alert. **Refund-object accounting?** Refunds restore stock if `_restock_refunded_items` is enabled. A bulk refund could theoretically push SKUs back to `instock`, never trips this alert. **Plugin-induced data shape variance?** ATUM Inventory Management updates on a 5-min delay; alert can lag. Stock Synchronisation across multiple Woo installs can produce alert clusters when sync runs. WooCommerce Subscriptions products sometimes track stock and trip alerts on renewal cycles. **Multi-currency, does it affect this alert?** No, inventory is currency-independent. **Why does Woo and Stripe disagree?** Stripe does not track inventory; the metrics are unrelated. **Today is jumpy, why?** Spike alerts are inherently event-driven. The 2σ baseline filter prevents most false positives; rolling-1h evaluation auto-clears once velocity returns to baseline. **Sync-lag from self-hosted server slowness?** Indexer running every 10 min means OOS state can be up to 10 min stale. After host recovery, watch for a delayed alert burst as catch-up reflects intervening events. **My WP Admin shows fewer OOS flips, debug?** 1. Confirm timezone alignment. 2. Refresh WP Admin (purge object cache). 3. Check whether a custom inventory plugin overrides `_stock_status`. 4. If the gap persists, contact support. *** ### Tracked live in Vortex IQ Nerve Centre *OOS Spike Alert* is one of hundreds of KPI pulses Vortex IQ tracks across WooCommerce and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English. [Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.