There's a quiet kind of confidence that comes from finally getting a spreadsheet to do the heavy lifting for you, and the question that started this thread is a perfect example of that small but meaningful milestone. The user wants to compare two columns of Buy, Sell, N/A, and blank values, then produce a single third column that reflects the most decisive signal available. On its face, this is a simple logic problem. But as the poster correctly notes, the real challenge isn't the comparison itself; it's defining what "decisive" means when one column is silent. That's not a spreadsheet problem. That's a data modeling problem wearing a spreadsheet's clothes.
This kind of task sits right at the intersection of two common struggles we see in our community. On one side, there's the challenge of Beyond Similarity Scores: Deduplicating Data with Deterministic Stages, where the hard part isn't the match but deciding what a match means. Here, the same principle applies: the formula is easy once you decide on the hierarchy of values. Is "Buy" stronger than "Sell"? Does a blank get ignored or treated as an active vote against the other column? The user's logic says blank and N/A are placeholders, not votes, which is a reasonable and practical stance. On the other side, there's the eternal battle of preserving structure while transforming it, much like the Power Query help spitting data from a column into multiple new column post where the goal is to reshape, not destroy, information. The user here isn't asking for a hack. They're asking for a rule.
Our honest take is that this is less about the formula and more about the philosophy of your data. If you treat blank as "no opinion," then the logic is straightforward: check if either column has a Buy or Sell, and if both have one, prefer the one that appears. But if you're not careful, you can build a rule that silently drops conflicting signals. For example, what if Column A says Buy and Column B says Sell? The user didn't mention that case, and that omission is worth pausing over. The question isn't just "how do I combine these two columns?" but "what am I willing to lose when they disagree?" That's the kind of decision that separates a quick fix from a durable workflow. We'd tell this user to write out the full truth table first, including all 16 possible combinations of the four values, and then decide which ones are even possible in their world. Because the formula itself is a one-liner. The clarity of intent is the real deliverable.
What we appreciate most here is the instinct to ask for help before building something brittle. That's the same spirit behind Protecting Formula Columns While Copy-Pasting Rows, where the risk isn't the logic but the accident waiting to happen during manual work. The user's instinct to put the comparison in a third column is the right one, but the next step is to make that column robust to future edits, not just current data. So here's the concrete takeaway: define your value hierarchy explicitly, test the edge case where both columns have conflicting signals, and if that case can't happen, say so in a comment. Because the spreadsheet will remember what you meant, but only if you tell it.