The average duration of VNYUX is reported to be 5.9 years and average maturity 6.4 years. Perhaps this fund is long-term in name only.
For comparison, VCAIX (California intermediate-term) has 5.5 and 4.9 for those numbers, while
Intermed tax-exempt VWIUX has 5.5 and 4.9 as well, with
Vanguard intermediate-term VBILX has 7.3 and 6.5.
What do you see about the NY fund that worries you?
It's all about market timing, uh, I mean rebalancing, uh, I mean opportunistic rebalancing, uh, I mean short-term opportunistic rebalancing due to a short-term change in one's asset allocation.