Share price of Alibaba Group Holding Ltd has come at a crossroad, as its 63 percent stocks are turning sellable upon the expiration of lockup.

The shares lockup ended Saturday, freeing up the e-commerce behemoth's biggest shareholders to sell stock starting Monday.

Investors shaken by its $128.5 billion market slump are jittering over further plunge, as Yahoo, Alibaba's biggest shareholder with 15 percent stake, hasn't pledged to keep its holding, according to Bloomberg.

Earlier this year, Yahoo CEO Marissa Mayer announced the company planned to spin off its 384 million shares stake in Alibaba, as the move would enable it to avoid paying multibillion-dollar tax.

According to Bloomberg, SoftBank chairman Masayoshi Son said in May his company would hold its 798 million shares "instead of cashing in."

Billionaire co-founder and vice chairman Joseph Tsai also pledged in August that he and executive chairman Jack Ma Yun had "zero intention" to sell. The two hold a combined 269 million shares, or about 10 percent of the stock that has just been unlocked.

The end of the trading restriction will free sales of nearly 1.6 billion shares, with the stocks totaling a market value of about $105 billion, said Bloomberg.

Alibaba closed at $65.75 on Friday, falling below its $68 issue price when the e-commerce giant debuted at the New York Exchange in September last year, raising a record $25 billion. According to the news organization, its market value has slumped $128.5 billion from its peak in November.