Why does IWDA have a 5-star Morningstar rating while VT has a 3-star Morningstar rating?
The star rating is not very important and more about marketing than anything else. Best to read the full report. By the way VT is 3-stars but holds a "Silver" analyst rating. You can read up to understand the difference between their star rating and the gold/silver/bronze rating.
Roughly (pls read up to confirm), the star rating for funds/ETFs (note: stocks are different rating system) is backward looking against peers while the gold/silver/bronze rating is forward looking.
