Delta

Delta in action

Inspiration

Over 70% of young investors say they don’t understand why stock prices move, even though they see charts every day. Prices change constantly, but the reasons are buried behind complex financial data and jargon that assumes years of experience. As a result, many teens either don’t invest at all, or treat the market like a guessing game. We built Delta to change that. By instantly explaining why a stock moved in clear, human language, Delta lowers the barrier to understanding and empowers the next generation to build real financial literacy instead of gambling. Charts move every day, but the “why” is locked behind complexity. Delta makes market movements understandable, so young investors can learn with confidence instead of guessing.

What it does

Delta takes stock price trends and explains the reasons behind price changes in plain, easy-to-understand language. Users can quickly see why a stock moved and gain actionable insights without needing deep financial knowledge. Instead of forcing users to interpret confusing charts or financial jargon, Delta analyzes recent price action and explains why a stock moved in plain language. Integrated APIS and AI surface likely drivers, such as earnings activity, broader market conditions, or unusual trading behavior.

How we built it

Delta is built as a full-stack web application using Next.js for a fast, responsive frontend and API layer. We ingest real-time and historical market data from Finnhub, which is processed to detect significant price movements and underlying signals. Each analysis is stored in MongoDB Atlas, enabling historical tracking and pattern analysis over time. To convert these signals into intuitive explanations, we integrated Google’s Gemini API, which generates concise, context-aware narratives grounded in the detected data rather than speculative predictions.

Challenges we ran into

Translating raw financial data into meaningful explanations without being too generic or repetitive.
Ensuring the backend efficiently processed data and communicated with the language model in real-time.
Balancing depth of insight with simplicity for users unfamiliar with finance.

Accomplishments that we're proud of

Creating a platform that instantly explains stock movements in context, which is uncommon in typical stock tools.
Making financial trends approachable and understandable for new investors.
Successfully integrating real-time data with LLM-generated insights seamlessly.
We spent a long time on the UI, making it look professional and sleek, and we are really happy with how it turned out

What we learned

How to design a backend that can handle both data storage and AI-powered analysis efficiently.
How context and comparison improve user understanding of stock trends.

What's next for Delta

Expanding to include predictive insights for upcoming stock trends.
Adding personalization features for users’ favorite stocks.
Integrating visual tools that highlight key factors behind price changes alongside the explanations.