Iron ore declined after its longest streak of weekly gains since January, hit by Beijing’s latest warnings about increased market supervision as its seeks to curb price rises.

The steelmaking material lost as much as 1.8% in Singapore after the National Development and Reform Commission said in a statement late Friday that it had met with major port operators to discuss iron ore inventory and storage matters, as well as to seek measures against hoarding.

The move followed the regulator’s earlier warning against hyping up iron ore prices, after it summoned some futures companies to reiterate its stance against speculation in the market.

Read More: China’s Property Stimulus Creates Iron Ore Price Conundrum

Prices have gained around 30% since mid-August amid optimism for more property-sector stimulus despite a lack of significant pick up in demand fundamentals. Market watchers remain hopeful China’s 1 trillion yuan ($140 billion) debt issuance announced last month will provide more affordable housing and lift steel markets, while some are calling for more aid from Beijing.

“Since the valuation of both steel and raw materials has entered an absolute high range, the continuing upward movement in the fourth quarter requires more powerful policy pivots,” according to Jiang Mengtian, an analyst at China-based independent researcher Horizon Insights.

Iron ore traded 1.4% lower at $131.95 a ton as of 10:06 a.m. in Singapore, after posting its fifth consecutive weekly gain on Friday. Futures in Dalian were down 1.4% and steel contracts in Shanghai retreated.