I have been wondering about this on several occasions too.
Did we not discuss this subject on the forum 10-12 months back?
I think the correct way to think about it is:
They sold convertible notes with strikes of 309.83.
That equals selling calls at 309.83 in terms of dilution.
They then bought 309.83$ calls to hedge dilution in case stock increased over that strike price.
And they sold warrants to reduce the 220m$ ish cost they paid for the 309.83$ calls.
Those warrants are essentially the sale of call options.
The warrants sold in the previous 2 offerings are described here on page s61 and s62.
I have trouble finding the strike of the warrants sold for the 2024 converts but the 2021's have a strike of 650.
The 2021 notes will result in dilution for shareholders at 650$.
424B5
Issuance of Warrants in Connection with 2019 Notes and 2021 Notes
In connection with the offering of our 0.25% Convertible Senior Notes due 2019, or the 2019 Notes, and the 1.25% Convertible Senior Notes due 2021, or the 2021 Notes, and our entry into certain convertible note hedge transactions, we sold warrants whereby the holders of the warrants have the option to purchase initially (subject to adjustment for certain specified events) a total of approximately 2.6 million shares of our common stock at a price of $512.66 for the 2019 Notes and a total of approximately 3.8 million shares of our common stock at a price of $560.64 per share for 2021 Notes. Taken together, the purchase of the convertible note hedges and the sale of warrants were intended to reduce potential dilution and/or offset potential cash payments upon the conversion of these notes and to effectively increase the overall conversion price of such notes from $359.87 to $512.66 per share in the case of warrants relating to 2019 Notes and from $359.87 to $560.64 in the case of warrants relating to 2021 Notes.
Issuance of Warrants in Connection with 2022 Notes
In connection with the offering of our 2.375% Convertible Senior Notes due 2022, or the 2022 Notes, and our entry into certain convertible note hedge transactions, we sold warrants whereby the holders of the warrants have the option to purchase initially (subject to adjustment for certain specified events) a total of approximately 3.0 million shares of our common stock at a price of $655.00. Taken together, the purchase of the convertible note hedges and the sale of warrants are intended to reduce potential dilution and/or offset potential cash payments upon the conversion of these notes and to effectively increase the overall conversion price of such notes from $327.50 to $655.00 per share.