HAL calculates a SOTP: Sum Of The Parts valuation every year. This year they will publish that on March 26th. It uses multiples of profit to valuate companies owned by HAL that are not publicly listed and traded. It should be higher than the book value (Net Asset Value of EUR 163 per share). The current share price of EUR 143 seems low in that light.
One open question is whether the authorities will authorize the sale of Grandvision to
EssilorLuxottica. This deal has driven GrandVision's share price and thus HAL Trust's Net Asset Value higher.
HAL owns 49% of CoolBlue which will get competition from Amazon which is re-entering the Dutch market. (Full disclosure: I own Amazon shares through ValueMachinesFund.)