(Reuters) - Shares in MicroStrategy ( MSTR ) were down 13% on Tuesday as bitcoin fell after the company announced it had completed a $603.75 million convertible debt offering - its second in a week - to raise money to buy bitcoin.

The deal, used by the company to raise money to buy bitcoin, follows an $800 million convertible offer that it announced it had completed just a week before.

The company, which also said on Tuesday that it bought 9,245 bitcoins for $623 million between March 11 and March 18, saw its shares tumble as low as $12,750, which was their lowest level since March 7. Bitcoin was last down 5.9% at $63,424.

The latest sale was of 0.875% convertible senior notes due 2031 and convertible into cash or shares of MicroStrategy's ( MSTR ) class A common stock, or a combination of both.

Before Sept. 15, 2030, the notes would only be convertible after certain events and during certain periods, according to MicroStrategy ( MSTR ).

The conversion rate, which is subject to adjustment, is initially 0.4297 MicroStrategy ( MSTR ) shares per $1,000 principal amount of notes, or the equivalent to a conversion price of approximately $2,327.21 per share, according to the company.

MicroStrategy ( MSTR ) said this represents a premium of about 40% over the volume weighted average price of its shares on March 14, 2024, which was $1,662.1999.

MicroStrategy ( MSTR ) shares were still up more than 100% year to date.