If you had well read the FAQ and/or forum, you would notice that only "ships next day" items are likely to be on hand in the FT warehouse.

Stock status here are the stock status of the supplier of the item, not FT. Stock statuses are not updated in real time either.

Think of FT as your personal shoppers. You order it, then they send out for your items to fill your order.

You could also think of it in terms of an auto repair shop. They often have to send out for the parts to fix your car when they're not on hand.