Eastnine board chair Louise Richnau has increased her stake in the property group, purchasing 11,546 shares through her holding company Lotsberget.
The transaction, valued at just over SEK 0.5 million, was disclosed in a regulatory filing on Monday.
The purchase represents a direct vote of confidence from the company's top governance figure.
Insider buying of this magnitude is often interpreted by market participants as a signal that the stock is undervalued or that the board anticipates positive developments in the near term.
Richnau's move adds to the list of insider transactions that traders monitor for sentiment cues in the Swedish property sector.
Eastnine operates in a market environment where property valuations remain under scrutiny due to interest rate sensitivity and refinancing risks.