May proved a stagnant month for the Deloitte WA Index following on from gains in the previous month.
The market capitalisation of WA-listed companies increased by only 0.3 per cent for the month, closing at $153.6 billion.
Deloitte WA clients and markets partner Tim Richards said although the local markets were feeling the impact from decreasing iron ore prices, investors could still seek comfort from international equity markets, which had reacted positively to recent economic data.
The local equity market remained flat, with the All Ordinaries posting meagre gains of 0.1 per cent during the month.
Investor sentiment has largely shrugged off positive leads from international markets over the constant decline of iron ore prices and the softening in China's economy weighing in on Australian equities.
Big WA-based market movers in May included Wolf Minerals up 294.1 per cent, Aquarius Platinum up 261.5 per cent and TNG Limited up 88.2 per cent.