What the percentage on an order block actually means

Asked twice now in the public comments, both times the same way: is that number the ratio of buys to sells inside the block? It is not — it is the block's relative strength. That is my own caption's fault: the input used to say "Show OB buy/sell volume %", which is exactly what sends a reader looking for a split.

How the number is built

For each order block the indicator sums the volume that traded inside it, then divides that sum by the same sum of the heaviest order block currently active on your chart. The label answers one question: how heavy is this block against the heaviest one you can still see. A block reading 100 is the heaviest live block; one reading 40 carries about four tenths of the volume the heaviest does. There is no direction in it at all. A buy/sell split is computed internally but kept off the label on purpose: it reads as signal when it is mostly noise.

Why it moves when your block has not changed

The comparison is relative, so the denominator is not fixed. When price mitigates the heaviest block, that block leaves the chart and the comparison entirely, and everything left is re-scaled against the new heaviest one. A block that read 60 yesterday can read 100 today without a tick having touched it. The label describes the blocks in front of you now, not a permanent property of one zone.

Where the volume comes from

Volume inside a block is aggregated from a lower timeframe, M1 by default. MetaTrader builds every timeframe from M1 anyway, so wherever the M1 history is complete the aggregated sum equals the parent bar's own tick volume, and changing that setting will not move the label. It matters only where the history is short and the aggregation comes back partial. And on feeds that publish no real volume, which is most retail forex and CFD, this is tick volume — a count of price updates, not contracts.

Higher timeframe blocks are ranked among their own kind

In the paid version, blocks pulled from a higher timeframe are compared only against blocks of that same timeframe. An H4 block showing 100 is the heaviest H4 block, not the heaviest thing on the chart. One shared ranking would let the strongest H4 block dwarf every M15 block.

The caption is corrected in the next update, to "Show OB strength % (volume vs strongest OB)". Until then: read the number as strength, never as a split.

Nexus Order Block Workspace