(Reuters) – Australian corporate earnings were a “positive surprise” amid investor euphoria over better-than-estimate margins, but historical trends suggested results could change towards the end of the reporting season, Macquarie analysts said.

Companies have reported better-than-expected margins, often due to lower tax and interest costs, and most of them have exceeded market expectations so far this season compared to February, Macquarie said in a statement.

The positive earnings figures prompted investors to replenish their portfolios, especially after they had reduced their equity exposure in the wake of the recent correction at the beginning of the month, the analysts noted.

Cyclical retailers were the top performers last week, with shares in JB Hi-Fi posting their best weekly gain in more than four years after the consumer electronics retailer announced a special dividend and full-year earnings that beat forecasts last week.

Top telecommunications provider Telstra (OTC:) also caused a positive surprise by raising its profit forecast.

Investors seemed to take the earnings slump at Australia’s leading banks in their stride, focusing instead on positive aspects such as Commonwealth Bank of Australia’s (OTC:) lower bad loan provision and National Australia Bank’s (OTC:) stable margin.

The biggest disappointment, however, was Origin Energy, whose share price plummeted after a warning that profits in the company’s power generation business were likely to decline.

The cycle is slowing and the biggest uncertainty is how much it will improve in response to the rate cuts by the US Federal Reserve and the Reserve Bank of Australia, analysts said, adding that the positive momentum in the results faded towards the end, especially in the last week.

“Although the high proportion of expectations is positive, we would caution against extrapolating this trend to the rest of the reporting season.”

The bulk of the earnings season is still ahead of us, with iron ore majors BHP and Fortescue, energy giants Woodside (OTC:) and Santos, and supermarkets Woolworths and Coles all set to report their results in the coming weeks.