Ride-hailing rivals Uber and Lyft are racing to raise a combined $1.5bn by the end of the year, as investors become ever more sceptical of the lofty valuations attached to Silicon Valley tech companies.

相互竞争的打车应用优步(Uber)和Lyft正竞相筹集资金，至今年底两家公司合计将筹集15亿美元。目前投资者对硅谷科技公司的超高估值越来越怀疑。

Uber is seeking to raise $1bn and Lyft is aiming for $500m as the companies fight to build market share and finance expensive legal and political campaigns to back their business models.

优步正寻求筹集10亿美元，Lyft的目标是5亿美元，两家公司不但在争取扩大市场份额，还在砸重金进行昂贵的法律和政治活动，以支持它们的商业模式。

The fundraisings come at a time when it is becoming harder to gauge how investors will react to lossmaking start-ups. Payments company Square priced its IPO below its indicated range but then saw its shares initially pop 50 per cent when public trading started yesterday. Earlier this year, fund manager Fidelity marked down the value of its stake in messaging app Snapchat.

此轮募资展开之际，投资者对亏损初创企业的反应正变得难以评估。支付公司Square对其首次公开发行(IPO)的定价低于指导价范围，但昨日开始公开交易后，其股价当即暴涨50%。今年早些时候，基金管理公司富达(Fidelity)调降了其在即时信息应用Snapchat所持股份的估值。

Uber’s initial conversations with investors were based on a valuation of around $70bn. However, that figure has since come down, according to people familiar with the matter. Earlier this year, investors valued Uber at $50bn. Uber declined to comment.

优步与投资者最初的协商是基于700亿美元的估值。然而，据知情人士透露，此后这一数字已经下调。今年早些时候，投资者对优步的估值为500亿美元。优步拒绝置评。

Both companies are already among the tech sector’s most aggressive fundraisers, with Uber having raised more than $10bn, a record for a US tech start-up. Lyft is targeting a $4bn valuation ahead of the new fundraising, up from the $2bn level at which it raised money from investors in May.

这两家公司已经置身于科技行业最活跃的筹款者之列，优步已筹集到逾100亿美元，创下美国科技初创企业最高纪录。Lyft在此轮融资前的目标估值是40亿美元，而5月份该公司向投资者筹资时的估值水平为20亿美元。

“The air has gotten pretty thin where these valuations are,” said Max Wolff, chief economist at Manhattan Venture Partners, which brokers transactions in private company shares.

撮合私有企业股票交易的Manhattan Venture Partners的首席经济学家麦克斯茠尔夫(Max Wolff)表示：“对于这些估值来说，空气已变得相当稀薄。”

Both companies are heavily lossmaking, common among start-ups in Silicon Valley where growth is prized among early stage businesses. Uber has poured billions of dollars into its international operations to gain global market share.

优步和Lyft都严重亏损，这在硅谷初创企业中十分普遍，各方看重的是企业早期阶段的增长。优步已对其国际业务投入数十亿美元，以争夺全球市场份额。

Lyft, which has raised a total of $1bn, has invested heavily in US marketing as it tries to steal domestic market share from Uber. The company declined to comment on the fundraising but John Zimmer, co-founder, said: “We are growing faster than Uber in the US.”

Lyft在美国投入巨资开展市场营销，试图从优步手中夺取国内市场份额，该公司已总共筹集到10亿美元。Lyft拒绝对此轮筹资置评，但联合创始人约翰倠默尔(John Zimmer)表示：“在美国我们比优步增长更快。”

Yet Uber has revenues 10 times higher than Lyft’s, according to people familiar with the matter. It expects net revenues of about $2bn this year, they said. Lyft said it was taking in $1bn in fares a year, from which the company’s take would be $200m based on its normal cut.

但据知情人透露，优步的营收是Lyft的10倍，优步今年预计净营收约为20亿美元。Lyft表示今年收取的打车费应为10亿美元，该公司的提成应为2亿美元。