Yes, okay, that's kind of what I thought you were going to say. The only caveat I would add is that it is not solely large specs who are pushing the trend - commercials who are hedging short are the fodder for the long buying by LS, and vice versa. Without continued cooperation on both sides, there would be no trend continuation.
Yes, of course... Since we are talking about futures contracts, for each contract that one buys, there must be one, who sells it. If you add all together (net LS, C and SS positions), you will get 0. So in this respect, you are right: it is truly arguable how we interpret a trend.
The way I see it is this: LS are usually building up their positions in the direction of the trend. So if prices are going higher, they are decreasing their short positions / increasing their long positions and of course the opposite is also true --> if prices are declining, LS are decreasing their long positions / increasing their short positions. You can see this on the charts as well.
Fundamental perspective: the fact that LS are in the market for speculative purposes also supports this view. While a speculative participant (let it be large or small, doesn't matter) will buy in a market with the expectation of it to rally further, a commercial participant (producer or consumer of that commodity) will simply be in the market to hedge their normal business activities and they would be just Re-acting to market moves.
All the best,
Dunstan


