Shares up, Investment trusts down - Why?

[GliderRider]

Looking through my portfolio yesterday (Thursday), almost without exception, my shareholdings in individual companies were up; not a lot, but they were up. On the other hand every investment trust I hold had fallen. The shares are mostly AIM100, with a smattering of FTSE250, whilst the investments trusts are a bit of everything, UK, Far East, US Technology, Biotech and so on.

What would have caused this anomaly?

[xeny]

Pound strengthening drove down the IT prices as they're mostly foreign assets/income? Pass on the AIM stocks though.