The Novonix Ltd (ASX: NVX) share price was on fire again in September.
The lithium-ion battery technology company's shares were one the best performers on the All Ordinaries index with a 47% gain.
What makes this all the more impressive is that in August, the Novonix share price rose 75%.
This means its shares are now up by 436% since the start of the year.
Why is the Novonix share price shooting higher?
Investors have been bidding the Novonix share price higher over the last couple of months due to a number of positive developments.
One of those was its agreement with Phillips 66, which saw the US energy giant acquire a 16% stake in Novonix.
Phillips 66 believes this investment will support its development of an entirely domestic supply chain for the growing US electric vehicle (EV) market and other energy storage systems.
Whereas Novonix revealed that Phillips 66's investment will provide it with the capital needed to support growth and ongoing R&D. This includes continuing to scale its synthetic graphite production and developing new technologies for higher-performance energy storage applications.
What else is boosting its shares?
Also giving the Novonix share price a boost were changes in the S&P/ASX Indices at the September rebalance.
Those changes saw Novonix's shares join the ASX 300 index at the commencement of trade on 20 September.
When a share is added to an index it can often lead to increased demand on the buy side. This is due to index funds needing to buy shares.
In addition, some fund managers have strict investment mandates only allowing them to buy shares from certain indices. This could mean there were some fund managers waiting in the wings to invest once they were given the opportunity to do so.
Investors will no doubt be hoping that October is just as successful for Novonix's shares. Time will tell if it is.