The time it takes for Amazon rankings to stabilize can vary depending on a variety of factors.

Here are some of the factors that may affect how long it takes for Amazon rankings to stabilize:

1. Sales and sales performance: Amazon tends to associate higher-ranked products with products that have good sales performance. Therefore, if your product can maintain good sales and performance, your ranking may be more stable.

2. Product quality and reviews: Amazon considers product quality and customer reviews to determine rankings. If your product is of good quality and receives a lot of positive reviews, your ranking may be more stable.

3. Competition: If your product is in a highly competitive field, it may take longer for your ranking to stabilize. In a highly competitive market, other sellers may take various measures to improve their rankings, so you need to work hard to stay competitive.

4. Amazon algorithm updates: Amazon frequently updates its ranking algorithm to provide a better customer experience. This may cause changes and fluctuations in rankings. You need to always pay attention to Amazon's updates and adjust and optimize your products and sales strategies accordingly.

To sum up, the stability of Amazon ranking depends on many factors and there is no definite time. However, by maintaining good sales performance, customer reviews and competitiveness, and keeping an eye on Amazon's updates, you can increase your ranking stability.