Thanks for the kind words. I think I understand what you were...

My pleasure. Yeah, I'd expect a Ceasing notice (F605) from them shortly.

Thanks for the kind words. I think I understand what you were driving at. The whole disclosure issue in this context relates to the percentage of (voting) control that a holder can exercise over a company, rather than the actual share count.

As you may be aware, once a SH holds over 5% they are generally required to also lodge subsequent disclosures for changes of holdings for each and every 1% change (up or down). In your example if the holder increased from 18% to 18.52% after a merger, then I would imagine that no further disclosure would be required at this stage (because less than a 1% change). There are slightly more onerous obligations around takeover situations, however, but I'll assume they weren't at play for that holder (i.e. they didn't launch their own takeover).

The issue of Top 20 holder lists can be tricky and very laggy, I have found. I guess it depends on where you're getting that from (eg: broker/information platform or maybe published by the company directly on their website). It's also worth mentioning that it's important (imo) to understand what the list is actually reporting (eg: Registered holders, or Beneficial holders).

The list published by a listed company on their website or in an Annual Report will be that of Registered holders, which more often than not will contain a bunch of custodian nominees (banks/brokers) which the beneficial holders hold through. Not terribly insightful. There are third-party data aggregators out there (serving the corporate market) who compile monthly lists which look beyond the custodian nominees to report the more useful Beneficial holders. The only trick is that direct subscription to those more useful lists costs many thousands of dollars. For retail punters, depending on your general market data platform, it's possible it might report the beneficial holder data, rather than vanilla 'registered'. As a general rule, imo, if you're looking at list that contains very few (or zero) custodian nominee banks/brokers, then it may well be a beneficial list. Then there's the question of when it was last updated.

Hope that helps.