I did not see IBA down 10% some days ago. I suspect IBA's management doesn't worry about the day to day movements of IBA, nor do I.
Likewise I suspect XIN's management doesn't worry about the day to day movements of XIN's share price....nor do I.
Both companies have huge ownership stakes by company founders. Both founders know approximately what their company is worth and don't give a rat's #$%$ what the share price is on any given day...or what the peanut gallery on public msg boards think or post. Both founders work diligently to increase their companies value and their own net worth as long term share holders.