You can multiply them by investing in mining and icos. I was able to multiply mine thankfully
We can really multiply our holdings if we make a lot of effort to know where is the good place for you to earn bitcoin. I do trading and I can say, my bitcoin is growing with a help of my other income in a signature campaign.
Write good articles at this forum, acheaves merits and high ranks, after take part in signature bounty companies and earn bitcoins or other altcoins
This requires a lot of hard work and patience, if you want to earn bitcoin easily do trading but your profit will depend on how much knowledgeable you are in trading so basically, earning bitcoin is not that easy if we know nothing.