Bonuses in investment banks and securities firms are fulfilling the best and worst of expectations, following the start of the annual bonus season last week.

Pay in fixed income has been skewed heavily towards the top performers who bring in the most revenues. The fixed income sector has provided the lion's share of revenue for the industry this year, so star performers - especially managing directors in sales and trading - have seen their bonuses rise as much as 20%, according to capital markets specialists. Sources close to Morgan Stanley and Goldman Sachs, which kicked off the bonus round, said that bonus pools in fixed income were marginally smaller than last year, but that 'allocations were tilted towards lead rainmakers'.