I post my wave count every weekend when I am less busy, so probably that's why you see the wave counts change from time to time. For each chart, I draw two possible counts - which means two possible market movements in my opinion.
For example, about SP, on 03/12 my counts were either wave-4 was ending (blue line) or a big collapse (wave-3) was going to happen (red line). On 03/19, since a sharp downward movement occurred which voided the wave-4 scenario (because the size of wave), I corrected my counts to either a higher degree of correction (wave-d) was completed (blue line) or the 03/12's red line scenario was still valid.
You can find that some of my wave counts point to the same direction without ambiguity but some don't.
Here is my answer to someone's question in some other forum:
... So you draw a new version each week based on the new data (that week's data), because it is by definition "more accurate" right? How do you use these charts in your trading?
To answer your questions:
1. Yes, I update the counts every weekend based on the movements/patterns developed in the past week.
2. Good question! The beauty of trading with wave is that Elliott Wave Principles have some rules that you can use to validate the current wave count. I trade with those rules, and then it's very easy to know where the stop order needs to be placed for the current wave count.
It also has an example of using wave to trade from sakuragi_indofx, "Trading never been so easy eh,". Basically, it says that the wave-4 and wave-1 will not overlap, so you know where to place the stop order if that count is valid.