You may have seen that Rachel Reichenbach had a call with member of the Instagram Partnerships team, here's what I took from her post.
Instagram’s algorithm will either "reward or punish" you based on your usage of the app
There are over 500 different factors
The algorithm ranks your specific post by taking into account your use of Instagram as a whole
Think of it like school. One exam doesn’t determine your whole grade. You’ve gotta participate throughout the year in class, not just show up for one test and get an A on it.
Reels are currently boosted in the algorithm
Once the reels feature isn’t so new, it will likely be downgraded to normal weight
Ideal amount of reels per week is 4-7, start with at least 1 per week
Instagram currently has a team dedicated to finding good Reels (created using Instagram’s in app editor) for them to promote. If your reel is featured, they’ll show it to more people for around a month, leading to a ton of views
Use all Instagram features
They want to see "participation and school spirit". And they'll reward you for posting a combination of normal posts, Reels, IGTV, Stories, shoppable posts and even for using event stickers, filters, location tagging and so on in Stories.
What Instagram recommend posting per week
3 feed posts (Reels & IGTV you share to your grid count)
8-10 Stories (preferably 2+ per day)
4-7 Reels
1-3 IGTV
But as we know, that is completely unrealistic! So remember that consistency is key but consistency doesn’t mean frequency. The algorithm encourages posting more often. At the very least consistent over time (during your follower’s peak hours) so you could post 3 times a week on set days or every other day for example.