Since April 11, the ASX has posted seven straight weeks of gains, gaining almost 10 per cent, outperforming its developed market peers.

The best performing sector in the period was healthcare, rallying 14 per cent helped by the strong performance of investor favourite CSL. Also outperforming the broader market were the energy and materials sub indices, enjoying a period of stability in commodity prices, while financials received a boost from an interest rate cut at the start of May.

But at 5400 points, the market has met a resistance level and the relative smooth sailing that has allowed it to add more than 450 points is about to be overtaken by a return to macroeconomic instability, including the US Federal Reserve meeting and Brexit referendum, and end of financial year jostling.

Jakov Males, head of Australian equities at UBS Asset Management, said bond proxies, notably infrastructure and real estate investment trusts, as well as growth stocks, had ballooned to "extraordinary premiums" over the course of the rally.

"The re-rating has been indiscriminate and to historically high levels in absolute and relative terms," he said.

"Anything that shakes the faith in ultra-low interest rate policies and the ability of companies to deliver the significant growth factored into share prices, threatens these inflated parts of the market."

Peak Asset Management executive director Niv Dagan is also one with an eye on the US Federal Reserve's move towards monetary policy tightening as putting the brakes on the market rally.

The increasing probability that the US Federal Reserve will raise interest rates, in chair Janet Yellen's words "in coming months", is pushing the US dollar higher and setting an ominous tone for commodity prices, he said.

"I see commodities and gold at risk as the US dollar rallies," Mr Dagan said.

Gold stocks have already begun a descent following nine straight days of losses in the price of gold, slipping below $US1200 an ounce, a victim of US dollar strength, its longest rout in a year.

Newcrest Mining, the ASX's biggest gold miner, rose as much as 20 per cent through April and early May, but has already handed back half of those gains, and Mr Dagan said he expected more pressure.

Mr Males said while commodities may be caught up in such events, in the case of oil, prices are already below sustainable levels and supply remains under pressure due to geopolitical instability.

"But more importantly is the massive underinvestment over recent years," he said.

Ophir Asset Management portfolio manager Andrew Mitchell said volatility would pick up as the Fed moves further into its tightening cycle as early as June or July.

"While the volatility has died down from January levels we think this is temporary and investors should be prepared for more volatility ahead," Mr Mitchell said.

"The investment community is generally negative on the world, many investors are sitting on cash."

The macroeconomic events tie in with the end of financial year, and tax loss selling and fund manager "window dressing" ahead of the end of financial year mean June will be a month of selling, Mr Dagan said.

Bell Potter's Richard Coppleson said many investors move to offset their profits after big rallies in certain stocks by selling their losers and locking in tax losses to reduce their tax bill.

"In the past whenever we see tax loss selling it usually begins early, as the instos [institutional investors] move ahead of the pack and start their tax loss selling from late May," he wrote in his daily Coppo Report.

The more illiquid a stock, the bigger its fall in June will be and investors looking to sell illiquid stocks should sell early, ahead of the broader June selling, he said.

From mid to late June these stocks will bounce back hard, however, and historically it tends to last from the last week in June until the second or third week of July.

Mr Coppleson identified 50 of the worst performing stocks over the financial year that are vulnerable to tax loss selling. At the top of the list is Liquefied Natural Gas, which sank 86 per cent, Capitol Health, down 77 per cent, 1-Page, down 68 per cent, Cardno, down 64 per cent and Cudeco, down 62 per cent.