Things are clicking. Q2 looked strong. Sales are up, your ads are landing, and your bestsellers are moving fast. This year, ecommerce grew over 6% in Q1, about 1.5x faster than retail overall. That momentum is real, but it also means demand will hit harder this Black Friday.

If stock levels aren’t on your radar yet, the growth you’re seeing could cost you. Selling out might look good, but missed revenue and last-minute reorders won’t. Top SKUs, lead times, and promo plans are where most founders slip. These inventory gaps are the blind spots that quietly build into Q4 sellout risk. Spot them now, and you can still adjust. Ignore them, and someone else will take the sale.

Sign #1: Your Top SKUs Are Already Dipping Low

If your top sellers are sitting below 8 weeks of stock, you’re looking at more than just a small dip. It’s a clear warning. Black Friday doesn’t ramp up gradually. It hits hard, and the SKUs flying off the shelves now are the ones you’ll run out of first. Hoping things level out by fall is a gamble.

Stockouts jump during Black Friday, and up to 80% of shoppers won’t wait around. That can cut 4% or more from your revenue in a weekend. Run a sell-through check on your top 10 SKUs. If the numbers are tight, reorder now. Waiting might end up hurting you in ways you don’t expect.

Sign #2: You Haven’t Locked Reorders with Your Vendors

If your shipments aren't locked in, you're not in control. Lead times often start at six to eight weeks but end up taking ten or longer. With approximately 52% of US retailers dealing with port congestion and growing backlogs, delays are the norm, not the exception. Once production queues fill up, you either pay extra to rush shipping or watch your competitors stay stocked while you wait.

Founders who hold off until everything feels certain usually end up reacting too late. Lock in reorders now based on your forecast. You can scale back if needed, but you can’t speed up merchandise that was never ordered.

Sign #3: You’re Waiting on Your BFCM Calendar to Finalize Inventory

If you’re waiting to finalize your promo calendar before making inventory decisions, you’re cutting it too close. Discounts change how quickly products move, and planning promos without locking items on hand first is asking for a mismatch you can’t fix in November. Too often, founders build the perfect offer only to realize they don’t have the stock to support it.

Nearly a quarter of promotions end up stacking on top of each other, which eats into full-price earnings and creates unexpected inventory gaps. Start running scenarios now. Look at how a 20 or 30% discount could impact sales, then shape your inventory plan based on that. Guesswork is what drains margins. A clear forecast gives you room to sell with confidence.

Bonus Sign: You Don’t Have a Clear View of Cash Flow

If you’re still forecasting in an old spreadsheet, it’s only a matter of time until something slips. Juggling SKUs, channels, and promos without a real system throws off reorder planning and leads to missed reorders and tied-up cash. Inventory mistakes like overstock and stockouts cost businesses over a trillion dollars a year, mostly from bad forecasts and messy data.

Download our Ecommerce Cash Flow Statement Template to see exactly where your cash is going  and where you’ll need it most.

How to Avoid Stockouts and Stay Ahead This Black Friday

You don’t need to predict every spike in demand. You just need to be ready for it. If any of these signs sound familiar, now is the time to act. The brands that win Black Friday are not the ones with the biggest discounts. They are the ones who planned ahead.

Start with a solid forecast. Lock what needs locking. Then build your calendar around your Black Friday inventory plan, not what you wish you had in stock. Grab the free Q4 Inventory Forecasting Template and get prepared as the rush starts to build.