One of the portfolio firms of Seattle-based venture investor Ignition Partners has moved a step closer to an IPO this morning, setting estimated IPO pricing. Splunk, a developer of software used for real time indexing by enterprise companies, which is based in San Francisco, said Monday morning in a filing that it expects to price its IPO at between $8.00 and $10.00 a share. Ignition holds a pre-IPO stake in Splunk worth 12.1 percent of the company. Splunk has applied to list on the NASDAQ Global Select Market as SPLK. Initial IPO pricing ranges are usually set shortly before actual pricing of a company before a debut on the markets--usually anything from days to a few months before an IPO pricing.