Do you have an IPS (investment policy statement)?
Academic studies have shown that over long-term time periods market timing is responsible for less than two percent of the variance of investment returns; security selection is responsible for less than five percent; while asset allocation policy (the desired mix of stocks and bonds) is responsible for almost 92 percent of the total return variation (see chart). This is yet another reason why it is critical to document the desired asset allocation policy and other guidelines for the portfolio in a written IPS.