Insider buying is usually regarded as a bullish indicator, as few people should know a company better than its own directors.

The theory is that if they have the confidence to buy shares, it could be interpreted as a sign that things are going well and they expect them to appreciate in value.

Conversely, when directors sell shares, it is often regarded as a bearish indicator. After all, you would be unlikely to sell your shares if you felt they were about to increase in value.

With that in mind, let's now take a look at three ASX All Ords shares that have recently reported meaningful insider selling:

The first ASX All Ords share that has reported some major insider selling is audio-visual networking solutions provider Audinate.

A change of director's interest notice reveals that its chair, David Krall, offloaded a total of 100,000 Audinate shares through a series of on-market trades between 22 March and 27 March.

Krall received prices of between $20.70 to $22.36 per share for his sales, which equates to a total consideration in the region of $2.1 million.

Audinate explained that the chairman's sale was undertaken to fund an investment and for personal reasons. It said:

The disposal of 20% David Krall's shareholding in the Company is to allow an investment in a family asset and will be utilised for personal reasons. Following the sale, David Krall will retain 402,308 ordinary shares in the Company, representing approximately 0.5% of shares on issue.

This engineering and project delivery services provider is another ASX All Ords share that has experienced insider selling recently.

According to a change of director's interest notice, the company's founder and executive director, Bruno Ruggiero, offloaded a total of 1.35 million shares through off-market trades on 22 March and 25 March.

The release notes that Ruggiero received a total consideration of approximately $16 million from the sale.

Despite the large sale, the executive director still holds 1,650,520 Lycopodium shares.

Finally, one of this Africa based mineral exploration company's non-executive directors has been selling shares recently.

A change of director's interest notice reveals that Julian Stephens sold 3 million shares between 26 March and 27 March through a special crossing trade. The ASX All Ords share's director received $1.43 million from the sale.

The release notes that Stephens made the sale in order to settle outstanding personal tax obligations. He is left owning a sizeable 13,557,518 shares.