The Hong Kong Immigration Department are highly sympathetic to foreign nationals who find themselves with an employment visa sponsored by an employer that has had to make them redundant.
In this situation you can expect the employer to notify the HKID of the fact of your redundancy and therefore you need to act on the basis the Immigration Department are fully aware of the change in your employment circumstances resulting from the loss of your job.
Best practice now is for you to independently write to the Director of Immigration and advise them of what has happened to you. Do this within 14 days of the notification to you of your redundancy.
You can then expect that the HKID will then write back to you stating that it’s ok for you to remain in Hong Kong until your current limit of stay expires.
Assuming it is your intention to remain in Hong Kong, this should then provide you with sufficient time to make alternate arrangements to stay in here, either to find another employer or, if you’re so minded, to start up a new or join in an existing business.
In the meantime it is lawful activity to look for, interview and accept a new job offer.
And also pursue the possibility of starting up your own company or investing in someone else’s.
However, it is not lawful to take up a new job until you have secured the permission of the Immigration Department to do so, nor indeed to commence activity in any new business which you are involved with until the HKID have agreed that is ok for you to do this.
So your next move is to make a new application to the HKID either to change your employment visa sponsor to work for an alternate employer or make an application for an investment visa in respect of your new business endeavours.
The availability of the consent of the Immigration Department to these ends will be determined on the individual merits and the circumstances of the new application and should not be assumed as automatically approvable.
You still needed to pass the approvability test for these applications in their own right but you can rest assured it is unlikely the HKID will force you to leave Hong Kong just because you have, through no fault of your own, been made redundant from your job in the HKSAR.