top holders report, page-2

Comparing to Jan 30 Report it looks like:

Holder Jan 30 Feb 29
JPM 5.5M 4.5M
Perpetual 11.6M 11.6M
City Corp 18.7M 11.7M
National 8M 10.5M
HSBC 5.1M 5.2M
Satori 4.8M 4.8M
JPM Nominees 1.5M 4.5M

Theres is new player Cassa Trading whose on 4.9M who are they and why are they buying?
Why has City Corp sold 7M shares in 1 month is this Socius selling cos they got some cheap options?