Corporate bond issuance in the first five months of the year rose 15 percent year-on-year to VND91.6 trillion ($4 billion), according to the Hanoi Stock Exchange.

The ministry said in a statement that investors should not buy bonds based solely on their high coupon rate, as there are chances that they will lose out if the companies run into financial difficulties and are unable to repay their dues.

Analysts at brokerage MB Securities said that real estate companies were increasing their bond issuance amount to raise funds as banks tightened lending to limit bad debt. The State Bank of Vietnam had also tightened control over real estate sector borrowings to minimize risks.

The government is seeking to tighten corporate bond issuance following some companies issuing bonds worth 50-100 times their equity last year.

A government decree effective January 1 next year will limit bond issuance through private placement to three times the issuing entity’s equity.

It will also require a minimum six month gap between two issuances, a proposed rule that seeks to prevent businesses from raising money from a large number of investors via private placements.

The value of corporate bond issuances increased by 25 percent from 2018 to VND280 trillion ($12 billion) last year, according to SSI Securities Corporation.