Nervous that the rollercoaster of the equity markets might reach the end of its steady uphill climb and go into freefall, David Brown, a partner and securities analyst at Sit Investment Associates, is keeping a close watch on the world's central banks. Protecting profits is priority one, and there are plenty of profits to protect: For the 12 months ending in June, the firm's assets are up $2 billion to $13.7 billion.