revenue, COS and GPM

It's the same issue I addressed on your previous post https://opentuition.com/topic/gross-profit-margin-4 If margins are assumed to be constant - increased sales volume does not change GP% because cost of sales should also be increased for that volume. So if GP% increases without a valid explanation (e.g. sales prices were increased during the year but without a corresponding increase in costs of sales) - either revenue is overstated and/or cost of sales is understated (e.g. purchases are understated)

Yes!