Iceberg buy in CME futures?

This chart is of the CME Bitcoin futures. A new bar is made every 10 orders in volume. The bottom blue line is cumulative delta. Cumulative delta is all market buys minus all market sells. This tells us which direction market orders are generally pressuring. There is a divergence between price and cumulative delta on this chart, which we've seen before large selloffs. However, the context of this one is a little different. I believe the chart may be showing a large iceberg order.

During the period from about 10-11 AM ET there was extended selling according to my chart. Cumulative Delta shows market selling through the whole period. However, price was not able to get below 8450 despite orders selling into it. I cannot confirm this for sure without seeing the level2 at the time, but this was likely an iceberg order based on the hard line you see on the chart at 8450 where price could not push through. For those unfamiliar with this term, an iceberg order is a large limit order that refreshes the bid every time it is filled. So you might only see 1 bid at 8500, but as they sell 20 contracts go off there. This allows large players to accumulate positions without having to show it all on the level2.

In other words, someone may have just put about $.5 million in margin long in bitcoin futures.

Update: Looks like the order may be playing out. We just had a huge move up past 8700. It is unclear if that's all there is.