The market's biggest semiconductor index is on its longest-ever winning streak. Here's what could trip it up.

• The Philadelphia Semiconductor Index (SOX) is on a historic winning streak.
• The market's largest chipmaker index is up 38% in 16 days.
• Deutsche Bank sees one supply chain factor that could stop its progress.

If you need an illustration of the renewed bullishness for AI among investors, look no further than the market's top chip index.

The Philadelphia Semiconductor Index (SOX) wrapped up a 16-day winning streak at Wednesday's close, rising 38%, and continues to gain in Thursday's session. It is the longest streak of gains for the index in its 32-year history.

The index tracks the universe of semiconductor companies, including chip titans like Nvidia and Broadcom, chip-design firms like Arm Holdings, and red-hot memory makers like Micron Technology.

Deutsche Bank highlighted the index's growth in a note to clients on Thursday, attributing much of its recent success to Nvidia, which is up more than 22% over the past 16 days. The latest leg of the market's AI boom has helped push the Nasdaq Composite to its own historic win streak, with the tech-heavy index hitting its longest streak of gains since 1992 last week.

While the rally appears to have room to keep going, Deutsche Bank analysts said one factor stemming from the Iran war presents an ongoing risk: disruptions to the helium supply chain.

"Helium is used for cooling and creating inert, non-reactive environments during production, and has no viable substitute for some applications," analysts noted. "So, with major producer Qatar shipping its supply through the Strait of Hormuz, initial fears of a production halt because of Iranian attacks were significant."

They added that SOX fell more than 15% after the war first broke out before reversing course and embarking on its current winning streak. The immediate negative momentum has ceased, but Deutsche Bank noted that the price action underscores the fragility of AI supply chains.

That said, the analysts said the strength of the AI trade can continue. Other top banks agree. JPMorgan this week boosted its S&P 500 target, pointing to fresh excitement for AI as one of the big drivers.

"This run has been significantly bolstered by strong earnings reports and optimistic forward guidance from key industry players, against a backdrop of hyperscaler capital expenditure expected to exceed $700 billion this year," Deutsche wrote.

The analysts cited strong earnings from Taiwan Semiconductor Manufacturing Company and ASML, highlighting demand for AI chips and manufacturing services. They also noted that United Microelectronics Corporation, Taiwan's second-largest chipmaker, is expected to post strong growth.

"This has all reinforced the narrative of a powerful, AI-driven demand cycle," Deutsche added. "So, the talk of an AI bubble from last year has receded for now, with investors moving back into high-beta technology and semiconductor names."