Interpreting the Zweig Breadth Thrust buy signal

Preface: Explaining our market timing models We maintain several market timing models, each with differing time horizons. The "Ultimate Market Timing Model" is a long-term market timing model based on the research outlined in our post, Building the ultimate market timing model. This model tends to generate only a handful of signals each decade.
The Trend Asset Allocation Model is an asset allocation model that applies trend-following principles based on the inputs of global stock and commodity prices. This model has a shorter time horizon and tends to turn over about 4-6 times a year. The performance and full details of a model portfolio based on the out-of-sample signals of the Trend Model can be found here.

My inner trader uses a trading model, which is a blend of price momentum (is the Trend Model becoming more bullish, or bearish?) and overbought/oversold extremes (don't buy if the trend is overbought, and vice versa). Subscribers receive real-time alerts of model changes, and a hypothetical trading record of the email alerts is updated weekly here. The hypothetical trading record of the trading model of the real-time alerts that began in March 2016 is shown below. 

The latest signals of each model are as follows:

• Ultimate market timing model: Sell equities*
• Trend Model signal: Neutral*
• Trading model: Neutral*

* The performance chart and model readings have been delayed by a week out of respect to our paying subscribers.

Update schedule: I generally update model readings on my site on weekends. I am also on Twitter at @humblestudent and on Mastodon at @humblestudent@toot.community. Subscribers receive real-time alerts of trading model changes, and a hypothetical trading record of those email alerts is shown here.

Subscribers can access the latest signal in real time here.  A ZBT buy signalThe market flashed an extremely rare Zweig Breadth Thrust buy signal late Friday. Without going into a lot of detail, the ZBT buy signal is triggered when the market surges from an oversold to an overbought reading within 10 trading days, which it managed to achieve on Friday.

How should investors interpret this buy signal? At first glance, it appears to be an excitingly bullish development, or a "what's the credit limit on my VISA card" buy, but I have doubts.
 The full post can be found here.