Just days after admitting in a published report that he tried to tamper with a funding round of his biggest rival, Uber CEO Travis Kalanick appears to be piecing together a round of his own.

The five-year-old urban transportation company already has banked about $1.5 billion from investors, and was valued at approximately $17 billion in June after raising money to speed its international expansion. That makes it the Bay Area's highest-valued private company. (Previously, in August of 2013, it was valued at a measly $3.5 billion.)

And now, according to a report by the Financial Times, the company is aggressively going in for another round before year's end. As the Times reports:

The fundraising will test private investors' appetite for growth in the technology sector, which has so far shown little sign of abating despite some venture capitalists' concerns about the rate at which start-ups are consuming cash.

After strong demand among investors this summer, Uber hopes to take the opportunity to build a balance sheet "proportionate" to the scale of its business, according to a person with knowledge of its fundraising plans.

Uber may be trying to get its valuation up in preparation for an IPO. Consider that at its last funding round before reaching profitability and going public, Facebook was valued at an implied $15 billion. The newly anticipated round could total up to $1 billion in cash and value Uber at as much as $25 billion, ReCode reports.

Or, as TechCrunch reports, the deal might not offer full equity to investors; instead it could be structured as convertible debt, to reduce its risk of dilution. (Another voice to consider: the Wall Street Journal reported Friday that the round could total as much as $2 billion.)

Although most spectators seem to think it's too early for Uber to go public, this sort of fifth round of funding--known as Series E--is a rare step, and usually is done in preparation for an IPO, in order to boost or stabilize a private company's valuation.

Uber was founded in 2009 by Kalanick, the now-notoriously combative serial entrepreneur, alongside his buddy and StumbleUpon creator Garrett Camp. The service now operates in about 220 cities around the globe. Just glance at its jobs page for a glimpse of near-future expansion plans.

The funding would mean Uber has even deeper pockets for international expansion, taking on competitors, and bringing on big-name hires. In August, Uber hired President Barack Obama's 2008 campaign manager, David Plouffe, to lead policy, strategy, and political activities. Just today it confirmed that it brought on Tom Fallows, the creator and head of Google's same-day-delivery service, Google Express. And recently, the company poached Lyft COO Travis VanderZanden.

And then there's the "taking on competitors" question, especially regarding Uber's arch-rival, Lyft. But whether the massive anticipated addition to Uber's war chest means that it could be ultimately eyeing an acquisition of one or more of those competitors remains to be seen.