In a sign of demand for the shares of Splunk, the venture-backed developer of enterprise indexing software which is backed by local investor Ignition Partners, Splunk has revealed in a filing that it is upping its estimated IPO pricing range to between $11.00 and $13.00 per share. The estimated IPO range is above and earlier range of between $8.00 and $10.00 per share. Ignition's investment in Splunk is overseen by John G. Connors, who serves on Splunk's board of directors. Connors has been on Splunk's board since August of 2007.