Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Does it make sense to talk about an ETF or index in terms of technical indicators?
Yes, it makes sense. Like Lagerbaer says, the usefulness of technical indicators can not be answered with a simple yes or no. Some people gain something from it, others do not. Aside from this, applying technical indicators (or any other form of technical analysis - like order flow) to instruments which are composed of other instruments, such as indexes (more accurately, a derivative of it), does make sense. There are many theories why this is the case, but personally i believe it is a mixture of self fulfilling prophecy, that the instruments the index is composed of (like the stocks in the S&P500) are traded in similar ways as the index (or rather a trade-able derivative of it like ETFs and futures), and the idea that TA just represents human emotion and interaction in trading. This is a very subjective topic, so take this with a grain of salt, but in contrast to JoeTaxpayer i believe that yields are not necessary in order to use TA successfully. As long as the given instrument is liquid enough, TA can be applied and used to gain an edge. On the other hand, to answer your second question, not all stocks in an index correlate all the time, and not all of them will move in sync with the index.