Based on the skills and experience listed, Stephen Wong could charge an estimated hourly rate of $125. This is a conservative estimate considering his role as a CPA, with expertise in auditing and financial accounting. The average hourly rate for a CPA in the San Jose area is around $100-$150, but Stephen's additional skills in US GAAP and financial reporting may justify a slightly higher rate. Additionally, his proficiency in Microsoft Office and writing skills are valuable assets in the industry. Overall, an estimated rate of $125 per hour is a reasonable estimate for Stephen's expertise.