Does anyone recall the standard way of pricing barrier options ? The way the street does it, as opposed theory

I was under the impression that the bog standard methods that prevail in FX and have been covered by Wystup dominate.  I may be wrong abt that.

A knock-In option is a type of barrier option that only comes into existence when the price of the underlying security reaches a specified barrier at any point in time during the option's life. Once a barrier is knocked in, or comes into existence, the option will not cease to exist until the option expires.

Knock-in options may be classified as up-and-in or down-and-in. In an up-and-in barrier option, the option only comes into existence if the price of the underlying asset rises above the pre-specified barrier, which is set above the initial asset price. Conversely, a down-and-in barrier option only comes into existence when the underlying asset price moves below a pre-determined barrier that is set below the initial asset price.

For example, assume an investor purchases a up-and-in call option with a strike price of $60 and a barrier of $65, when the underlying stock was trading at $55. Therefore, the option would not come into existence until the underlying stock price moved above $65.

Soft or plain? Double or single? DEM or EURO?

Does anyone recall the standard way of pricing barrier options ? The way the street does it, as opposed theory

Wow this sat for a long time without an on-point reply.  I would say the introductory paragraphs of Austing and Li's recent paper on model-independent barrier pricing accurately describe what the street does: everyone has their own in-house variation of a local/stochastic volatility model.  The details vary, but the final results are similar.  Austing & Li 2017 : "Model-free valuation of barrier options" https://www.risk.net/media/download/949701/download