Yes, all profs know about resistance starting at ~2.70.....
But, “big blocks” at this (or other key) levels are often not exactly “for sale”. It’s just a part of “price management” (by mms/profs). That is standard (necessary) procedure - so-called “check on sellers” (often used just to get read of parties/strategies are ready for fast profit under the resistance - read old posts for detail). The “big-blocks” objectives are often trivial - to impress people/retailers, and to push them selling lower.... Should there be not enough sellers under the big-block) - the "block" will move higher...., again and again. Of course, some "big blocks" also "collect" a number of real "active orders" (from short-term strategies) ready to be actually executed. That's why sometimes you may see some (real) selling-volume, indeed, but its size could be much lower than the actual total block-volume you saw.
Again, remember that at (important) “key levels” (like that resistance zone at ~2.70-2.72) one usually may expect quite enough "old news", “fake advices”, misleading publications, rumors, etc., etc., as there are always enough prof-parties (with certain “prof resources“) interested in very certain “price directions”. So, be very careful reading/trusting all such stuff, especially when prices are approaching certain (strategic) level. Don’t forget that a “strategic” long-term consolidation at ~2.72 was predicted still in Sept-Oct 2013, and actually took place almost a year ago (check old posts for details). Since that, this strategic zone (~2.70-2.72) was confirmed several times (the last time it was just a few months ago - last Nov)....