Why steemit rewards price go down and sometimes go up? (explanation for beginners)

Many of us sometimes notice that the rewards indicated in your posts sometimes go down as time goes by. It has happened to me at least three times, as my rewards are usually low :)

For example the highest reward I got was in this post, which can be seen in the image, initially the value was in the 150 steem dollars, but as the days went by the value was decreasing, staying at 100.73 steem dollars.

As you can see I was very sad with this price drop :(

And today I noticed that in one of my posts the value does not stop rising, initially it was around 50 steem dollars and now reached 80 steem dollars :)

As you can see in the image below, the value reached 82.61 steem dollars.

Of course I was very happy, but I wonder why this happens?

So I was researching here at steemit and I think I figured out why?

The rewards indicated in your posts are based on a 7-day moving average on the steem price.

If the price of the Steem dollar falls, then the estimate in your posts will slowly decrease to reflect this.

If the price of the Steem dollar increases again, it will increase slowly to meet the new price.

If you notice the value of Steem rose to $ 8.04, that's why the value of my reward went up so much.

I hope you have explained well and I hope it is true what I am saying :)