14-Feb-2021: Just to add to @Scherobi's "Top20" straw on ORG, AustralianSuper has been Australia's largest industry super fund for some years, and now claim to be Australia's largest super fund (of any type). They have an option for their members called "Member Direct" where you can invest up to 80% of your superannuation balance in a range of ASX300 companies and/or in a range of ETFs, which you can choose yourself. It's basically a SMSF (self-managed super fund) option, without the compliance headaches, because AustralianSuper look after all of the compliance, paperwork, reports, and tax for you. They charge a little more for that option than they do for their managed options, but they are still very competitive compared to non-industry funds or traditional SMSFs.
A growing number of AS members use that "Member Direct" option. I did, when I was an AustralianSuper member. I managed to grow my account balance at a good clip for a few years, then rolled that entire balance into my second industry super fund, Cbus, after Cbus started to offer a similar service which they call "Cbus Self Managed" - and I now have only one super fund - so no longer use AustralianSuper.
The point however is that the reason for the regular changes in the substantial holdings of companies by large industry funds like AustralianSuper is purely down to the movements within their individual members' "Member Direct" portfolios, so whenever there is a net movement of -1% or +1% across the entire AS membership, AS is required to lodge a notice to notify of the change. This does not reflect that AustralianSuper themselves are more or less bearish or bullish on the company (in this case, on ORG), just that enough members had either added more ORG or sold down ORG to warrant a change notification.
Outside of that "MemberDirect" option (where members are choosing themselves exactly which companies they want to hold within their own super portfolio), AustralianSuper have around 170 in-house investment professionals working for them, and they also use external well-respected fund managers to manage some of their other investment options, such as their "conservative", "balanced", or "growth" options.
Sometimes when you view a "Top20" list, it's hard to work out whose money is ultimately being represented by the names you see. For instance, when you see HSBC or Citicorp popping up across the Top 20, it's not always clear who they are managing that exposure for. Sometimes it is, sometimes it's not. It's an interesting thing to monitor, but it's sometimes hard to draw much in the way of useful inferrences from the data. I tend to focus more on what management and board members hold, and particularly whether they are reducing or increasing their exposure to the company. With larger companies, those guys won't always make the top 20 list, but all board members have to lodge notifications of their holdings, no matter how small. Also, watch out for directors or management who are only increasing their exposure via free shares or vested options, rather than buying shares on-market - at market prices. On-market purchases are the things I look out for the most.