A vibe-coded alternative to YieldGimp

A developer created a free, open-source web tool at mazzo.li/gilts/ as an alternative to YieldGimp for evaluating UK gilts, after YieldGimp became an app. The tool, built with an LLM in minutes, requires users to input a price rather than using market price, and allows selecting a tax rate for gross equivalent yield. The source code is on GitHub.

If you’re a UK tax resident, short-term low-coupon gilts are the most tax efficient way to get savings-account-like returns, since most of their yield is tax free. This makes them very popular amongst retail investors, which now hold a large portion https://archive.is/cEUtf of the tradable low-coupon gilts. YieldGimp.com http://YieldGimp.com used to be a great free resource to evaluate the gilts currently available. However, it was recently turned into an app rather than a simple webpage. I’m not even sure if the app is free or paid, but I do not want to install the “YieldGimp platform” to quickly check gilt metrics when I buy them. So I asked my LLM of choice to produce an alternative, and after a few minutes and a few rounds of prompting I had something that served my needs. It is available for use at mazzo.li/gilts/ https://mazzo.li/gilts/ , and the source is on GitHub https://github.com/bitonic/gilts-app . It differs from YieldGimp in that it does not show metrics based on the current market price, but rather requires the user to input a price. I find this more useful anyway, since gilts are somewhat illiquid on my broker, so I need to come up with a limit price myself, which means that I want to know what the yield is at my price rather than the market price. It also lets you select a specific tax rate to produce a “gross equivalent” yield. It is not a very sophisticated tool and it doesn’t pretend to model gilts and their tax implications precisely the repository’s README https://github.com/bitonic/gilts-app/blob/master/README.md yield-model-used has more details on its shortcomings , but for most use cases it should be informative enough to sanity-check your trades without a Bloomberg terminal.