The ETF That Trades While Tokyo Sleeps

A New York--listed ETF holds a global equity portfolio: $60\%$ of its value is US stocks and $40\%$ is Japanese stocks. It is $11{:}00$ a.m. in New York. The fund's last published net asset value, struck at yesterday's US close, was $\$100.00$ per share -- $\$60.00$ from the US sleeve and $\$40.00$ from the Japanese sleeve, where the Japanese holdings were marked at the Tokyo close preceding it, and Tokyo has not traded since.

Since that Tokyo close: Nikkei futures, which trade essentially around the clock, are up $1.5\%$, and the yen has weakened $0.5\%$ against the dollar. The US sleeve is, at this moment, worth exactly $\$60.00$ per fund share.

What is the ETF worth right now? A client points out that the fund is quoted at $\$100.40$, "a premium to NAV," and asks whether that is free money. What do you tell him?